Adjustable headgear tubing for patient interface

Abstract

To provide a positioning and stabilising structure for holding a seal-forming structure in a therapeutically effective position on a patient's head.SOLUTION: A positioning and stabilising structure 3300 may include at least one gas delivery tube 3350 for delivering a flow of air to an entrance to a patient's airways via a seal-forming structure. The at least one gas delivery tube may be constructed and arranged to contact, in use, at least a region of the patient's head superior to the otobasion superior of the patient's head. The positioning and stabilising structure may include an adjustment mechanism 3360 for adjustment of a length of the at least one gas delivery tube to enable the positioning and stabilising structure to be fitted to heads of different sizes. The positioning and stabilising structure may include a biasing mechanism. The biasing mechanism imparts a biasing force along at least a part of the length of the at least one gas delivery tube to urge the seal-forming structure towards the entrance to the patient's airways in use.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

[0001] 1 Cross-reference to related applications This application claims the benefit of U.S. Provisional Application Nos. 62 / 281,322 and 62 / 330,371, which are incorporated herein by reference in their entireties.

[0002] 2. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not applicable

[0003] 3. Name of the organization for joint research and development Not applicable

[0004] 4 Sequence Listing Not applicable

[0005] 5. Technology Background 5.1 Technology Area The present technology relates to one or more of the detection, diagnosis, treatment, prevention and amelioration of respiratory-related disorders. The present technology also relates to medical devices or apparatus and uses thereof.

[0006] A particular form of the present technology relates to patient interfaces used in respiratory therapy, prevention and amelioration of respiratory-related disorders.

[0007] 5.2 Description of Related Art 5.2.1 The human respiratory system and its diseases The body's respiratory system facilitates gas exchange. The nose and oral cavity form the entrance to a patient's airways.

[0008] These airways comprise a series of branching tubes that become narrower, shorter and more numerous the deeper they go into the lungs. The primary function of the lungs is gas exchange, allowing oxygen to enter the venous blood from the air and carbon dioxide to leave. The trachea divides into the right and left main bronchi, which further divide to eventually become the terminal bronchioles. The bronchi constitute the conducting airways and do not participate in gas exchange. The airways further divide into the respiratory bronchioles and ultimately the alveoli. Gas exchange occurs in the alveolar region of the lungs, and this region is called the respiratory region. See: Non-Patent Document 1.

[0009] There is a range of respiratory diseases. Particular diseases can be characterized by particular manifestations such as apnea, hypopnea and hyperpnea.

[0010] Obstructive sleep apnea (OSA) is a form of sleep-disordered breathing (SDB) characterized by episodes of upper airway closure or obstruction during sleep. This is the result of an abnormally small upper airway combined with the normal loss of muscle tone in the tongue region, soft palate, and posterior oropharyngeal wall during sleep. This condition causes affected patients to experience breathing pauses typically lasting 30 to 120 seconds, sometimes 200 to 300 times per night. This can result in excessive daytime sleepiness, which can lead to cardiovascular disease and brain damage. This condition is common, particularly among middle-aged, overweight men, but patients often experience no symptoms. See U.S. Patent No. 6,244,999.

[0011] Cheyne-Stokes respiration (CSR) is another form of sleep-disordered breathing. CSR is a disorder of a patient's respiratory regulator, characterized by alternating periods of waxing and waning ventilation, known as the CSR cycle. CSR is characterized by repeated deoxygenation and reaeration of arterial blood. Because of the repeated hypoxia, CSR can be harmful. In some patients, CSR is accompanied by recurrent sleep arousals, which cause severe insomnia, increased sympathetic nervous activity, and increased afterload. See U.S. Patent No. 5,629,499.

[0012] Respiratory failure is a general term for respiratory disorders that refers to the inability of the lungs to take in enough oxygen or exhale enough CO2 to meet the patient's needs. Respiratory failure can include some or all of the following conditions:

[0013] Patients with respiratory failure (a type of respiratory insufficiency) may experience unusual shortness of breath during exercise.

[0014] Obesity hyperventilation syndrome (OHS) is defined as the combination of severe obesity and chronic awake hypercapnia in the absence of any other clear cause of hypoventilation. Symptoms include dyspnea, morning headache, and excessive daytime sleepiness.

[0015] Chronic obstructive pulmonary disease (COPD) encompasses any of a group of lower respiratory tract diseases that share certain common characteristics, including increased resistance to air movement, prolonged expiratory phase of breathing, and a decrease in normal lung elasticity. Examples of COPD include emphysema and chronic bronchitis. Causes of COPD include chronic smoking (the primary risk factor), occupational exposure, air pollution, and genetic factors. Symptoms include dyspnea on exertion, chronic cough, and sputum production.

[0016] Neuromuscular disease (NMD) is a broad term encompassing numerous diseases and illnesses that impair muscle function directly through intrinsic muscle pathology or indirectly through neuropathology. Some NMD patients are characterized by progressive muscle impairment, resulting in the inability to walk, wheelchair confinement, difficulty swallowing, respiratory muscle weakness, and ultimately death from respiratory failure. Neuromuscular disorders can be categorized as rapidly progressive or slowly progressive: (i) rapidly progressive disorders, characterized by muscle impairment that worsens over months and leads to death within a few years (e.g., amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers); (ii) variable or slowly progressive disorders, characterized by muscle impairment that worsens over years and results in only a modest reduction in life expectancy (e.g., limb-girdle, facioscapulohumeral, and myotonic muscular dystrophy). Symptoms of respiratory failure in NMD include: increasing general weakness, difficulty swallowing, difficulty breathing on exertion and at rest, fatigue, drowsiness, morning headache, and difficulty concentrating and mood changes.

[0017] Chest wall disorders are a group of thoracic deformities that result in ineffective connections between the respiratory muscles and the rib cage. These disorders are primarily characterized by restrictive obstruction and share the potential for long-term hypercapnic respiratory failure. Scoliosis and / or kyphoscoliosis can cause severe respiratory failure. Symptoms of respiratory failure include: dyspnea on exertion, peripheral edema, orthopnea, recurrent chest infections, morning headache, fatigue, poor sleep quality, and loss of appetite.

[0018] A range of treatments are available to treat or ameliorate these conditions, and preventative treatments for respiratory disease are also available to benefit otherwise healthy individuals. However, these suffer from several deficiencies.

[0019] 5.2.2 Treatment Continuous positive airway pressure (CPAP) therapy is used in the treatment of obstructive sleep apnea (OSA). Its mechanism of action is that continuous positive airway pressure acts as a pneumatic splint, for example, by pushing the soft palate and tongue forward or backward against the posterior oropharyngeal wall, thereby preventing closure of the upper airway. Because treatment of OSA with CPAP therapy can be voluntary, patients may choose not to adhere to treatment if they perceive one or more of the following about the device used to deliver the treatment: it is uncomfortable, difficult to use, expensive, or aesthetically unattractive.

[0020] Noninvasive ventilation (NIV) provides ventilatory support to a patient through the upper airway to assist the patient in breathing and / or maintain adequate oxygen levels in the body by performing some or all of the respiratory functions. Ventilatory support is provided through a noninvasive patient interface. NIV is used to treat CSR and respiratory failure in forms such as OHS, COPD, NMD, and chest wall disorders. In some forms, it can improve the comfort and effectiveness of these treatments.

[0021] Invasive ventilation (IV) provides ventilatory support to patients who are no longer able to breathe effectively on their own and may be provided using a tracheostomy tube. In some forms, the comfort and effectiveness of these treatments may be improved.

[0022] 5.2.3 Treatment system These treatments may be provided by a treatment system or device. Such systems and devices may also be used to diagnose conditions without treating them.

[0023] The treatment system may include a respiratory pressure treatment device (RPT device), an air circuit, a humidifier, and a patient interface.

[0024] 5.2.3.1 Patient Interface A patient interface may be used to provide a wearer with an interface to a respiratory appliance, for example, by providing airflow to the airway entrance. Airflow may be provided via a mask to the nose and / or mouth, a tube to the mouth, or a tracheostomy tube to the patient's trachea. Depending on the therapy being applied, the patient interface may form a seal with, for example, an area of the patient's face, thereby facilitating gas delivery at a pressure sufficient to disperse with atmospheric pressure for therapy implementation (e.g., at a positive pressure of about 10 cmH2O relative to atmospheric pressure). In other forms of therapy, such as oxygen delivery, the patient interface may not include a seal sufficient to facilitate delivery of a gas supply to the airways at a positive pressure of about 10 cmH2O.

[0025] Certain other mask systems may be functionally inadequate in this field. For example, masks intended for purely decorative purposes may not be able to maintain adequate pressure. Mask systems used for underwater swimming or diving may be configured to protect against water intrusion from higher external pressures and not maintain internal air at pressures higher than ambient.

[0026] Certain masks may be clinically unsuitable for this technology (for example, if the mask blocks airflow through the nose and only allows airflow through the mouth).

[0027] In certain masks, the patient must insert part of the mask structure into their mouth and create and maintain a seal via their lips, which may be uncomfortable or impractical in this technology.

[0028] Certain masks may be impractical for use while sleeping (eg, when sleeping on your side in bed with your head resting on a pillow).

[0029] There are multiple challenges in designing a patient interface. The face has a complex three-dimensional shape. The size and shape of the nose and head vary greatly between individuals. Because the head contains bone, cartilage, and soft tissue, different regions of the face respond differently to mechanical forces. That is, the chin or mandible can move relative to the other bones of the skull. The entire head can move throughout the respiratory treatment period.

[0030] These challenges can lead to one or more of the following: some masks can be intrusive, aesthetically undesirable, costly, poor fit, difficult to use, and uncomfortable, especially if worn for extended periods or if the patient is unfamiliar with the system. If the wrong size mask is used, this can lead to reduced compliance, reduced comfort, and poor patient outcomes. While masks specifically designed for aviators, personal protective equipment (e.g., filter masks), SCUBA masks, or anesthesia administration masks may be durable for their intended use, such masks may be undesirably uncomfortable to wear for extended periods (e.g., several hours). Such discomfort can reduce patient compliance with treatment. This is especially true if the mask must be worn while sleeping.

[0031] CPAP therapy is highly effective in treating certain respiratory conditions when patients comply with the therapy. If the mask is uncomfortable or difficult to use, patients may not comply with the therapy. Because patients are often encouraged to clean their masks regularly, if the mask is difficult to clean (e.g., difficult to assemble or disassemble), patients may not be able to clean the mask, which may affect patient compliance.

[0032] Masks for other uses (e.g., aviators) may be unsuitable for use in treating sleep-disordered breathing, and masks designed for use in treating sleep-disordered breathing may be suitable for other uses.

[0033] For these reasons, patient interfaces for CPAP delivery during sleep form a distinct field.

[0034] 5.2.3.1.1 Seal-forming parts The patient interface may include a seal-forming portion. Because the patient interface is in direct contact with the patient's face, the shape and configuration of the seal-forming portion may have a direct impact on the effectiveness and comfort of the patient interface.

[0035] Patient interfaces can be characterized in part according to the design intent of where the seal-forming portion engages with the face during use. In one form of patient interface, the seal-forming portion can include two sub-portions, one for engaging each of the left and right nostrils. In one form of patient interface, the seal-forming portion can include a single element that surrounds both nostrils during use. Such a single element can be designed, for example, to rest on the upper lip and nose bridge regions of the face. In one form of patient interface, the seal-forming portion can include an element that surrounds the mouth region during use, for example, by forming a seal on the lower lip region of the face. In one form of patient interface, the seal-forming portion can include a single element that surrounds both nostrils and the oral cavity region during use. These different types of patient interfaces can be known by various names depending on their manufacturer, such as nasal masks, full face masks, nasal pillows, nasal puffs, and oronasal masks. Oronasal masks can include compact full face masks without a forehead support. Alternatively, the oronasal mask may include a full face mask that seals around the nose and mouth entrance, with the nose seal including a cradle that seals under the lateral nasal cartilages.

[0036] A seal-forming portion that may be effective in one area of a patient's face may be inadequate in another area due to, for example, different shapes, structures, variability, and sensitive areas of the patient's face. For example, a seal on swimming goggles that rests on the patient's forehead may be inadequate for use on the patient's nose.

[0037] A particular seal-forming portion may be designed for mass production so that one design will fit, be comfortable, and be effective for a wide range of different face shapes and sizes. To the extent there is a mismatch between the shape of the patient's face and the seal-forming portion of the mass-manufactured patient interface, one or both may need to be adapted to form a seal.

[0038] One type of seal-forming portion extends around the periphery of the patient interface and is intended to seal against the patient's face when force is applied to the patient interface with the seal-forming portion against the patient's face while the seal-forming portion is engaged against the patient's face. This seal-forming portion may include an air- or fluid-filled cushion, or may include a molded or formed surface of a resilient sealing element constructed of an elastomer such as rubber. With this type of seal-forming portion, if the fit is improper, a gap will form between the seal-forming portion and the face, requiring additional force to press the patient interface against the face to achieve a seal.

[0039] Another type of seal-forming part uses a thin flap seal positioned around the periphery of the mask to provide a self-sealing seal against the patient's face when positive pressure is applied within the mask. As with the previous type of seal-forming part, poor fit between the face and the mask can require additional force to achieve a seal or the mask may leak. Furthermore, if the shape of the seal-forming part does not match the shape of the patient, the seal-forming part may fold or buckle during use, causing leakage.

[0040] Other types of seal-forming portions may include friction-fit elements that are inserted into the nostrils, for example, but some patients find these seal-forming portions uncomfortable.

[0041] Another form of seal-forming portion may use adhesives to achieve a seal, as some patients find it inconvenient to constantly apply and remove adhesives from their face.

[0042] A range of patient interface seal forming technologies are disclosed in the following patent applications (assigned to ResMed Limited: US Pat. Nos. 5,629,999; 5,629,999; and 5,629,999).

[0043] One form of nasal pillow is found in the Adam line manufactured by Puritan Bennett. Another nasal pillow or nasal puff is the subject of U.S. Patent No. 5,623,999, assigned to Puritan-Bennett Corporation.

[0044] ResMed Limited manufactures the following products that use nasal pillows: SWIFT® nasal pillows mask, SWIFT® II nasal pillows mask, SWIFT® LT nasal pillows mask, SWIFT® FX nasal pillows mask, and MIRAGE LIBERTY® full face mask. Examples of nasal pillows masks are described in the following patent applications assigned to ResMed Limited: U.S. Patent No. 5,623,999 (depicting, among other things, aspects of ResMed Limited's SWIFT® nasal pillows), U.S. Patent No. 5,623,999 (depicting, among other things, aspects of ResMed Limited's SWIFT® LT nasal pillows), U.S. Patent No. 5,623,999 and U.S. Patent No. 5,623,999 (depicting, among other things, aspects of ResMed Limited's MIRAGE LIBERTY® full face mask), and U.S. Patent No. 5,623,999 (depicting, among other things, aspects of ResMed Limited's SWIFT® FX nasal pillows).

[0045] 5.2.3.1.2 Positioning and stabilization The seal-forming portions of patient interfaces used in positive air therapy are subjected to corresponding air pressure forces that disrupt the seal, and therefore a variety of techniques are used to position the seal-forming portions and maintain a seal against the appropriate portion of the face.

[0046] One technique involves the use of adhesives, see, for example, U.S. Patent Application Publication No. US2010 / 0000534, but adhesives can be uncomfortable.

[0047] Another technique uses one or more straps and / or stabilizing harnesses. Many such harnesses are one or more of the following: poor fit, bulky, uncomfortable, and cumbersome. When designed to be worn on the patient's head, such harnesses may be referred to as headgear.

[0048] 5.2.3.1.3 Compressed air conduits In one type of treatment system, a flow of pressurized air is provided to the patient interface through a conduit in the air circuit that is fluidly connected to the patient interface such that when the patient interface is positioned on the patient's face in use, the conduit extends forward and away from the patient's face. This is sometimes referred to as an "elephant trunk" style interface.

[0049] Some patients find such interfaces unsightly, resulting in decreased patient compliance if they are discontinued. Additionally, if the conduit is connected to the interface in front of the patient's face, it may become easily entangled with bedding.

[0050] 5.2.3.1.4 Pressurized air conduits used to position / stabilize seal-forming structures Another type of treatment system that attempts to address these problems includes a patient interface in which the tubing responsible for delivering pressurized air to the patient's airway also functions as part of the headgear for positioning and stabilizing the seal-forming portion of the patient interface on the appropriate portion of the patient's face. This type of patient interface may also be referred to as one that uses "headgear tubing" or "conduit headgear." Such a patient interface allows a conduit in the air circuit that provides pressurized airflow from a respiratory pressure treatment device to be provided to the patient interface in a location other than in front of the patient's face. An example of such a treatment system is disclosed in U.S. Patent No. 6,277,693, the contents of which are incorporated herein by reference. In this patent, the conduit connects to a tube in the patient interface through a port positioned on the top of the patient's head during use.

[0051] Philips' DreamWear® nasal mask includes such headgear tubing. One problem with this mask is that the length of the headgear tube cannot be adjusted. Therefore, DreamWear® masks are supplied in different sizes to accommodate patients with different face sizes. However, this increases the complexity and cost of manufacturing the DreamWear® masks and increases packaging. Furthermore, supplying masks in separate sizes limits the range of head sizes that can be accommodated by patients (e.g., whether a patient's head size fits between the offered mask sizes).

[0052] Using a patient interface with headgear tubing may provide some advantages (e.g., avoiding conduits connecting to the patient interface in front of the patient's face, which can be unsightly and uncomfortable), but it is desirable that a patient interface with headgear tubing be comfortable while forming an effective seal with the patient's face when worn by the patient for extended periods of time while the patient is sleeping.

[0053] 5.2.3.2 Respiratory Pressure Therapy (RPT) Devices Air pressure generators are known for a wide range of applications (e.g., industrial-scale ventilation systems). However, air pressure generators for medical applications have specific requirements that cannot be met by more common air pressure generators (e.g., the reliability, size, and weight requirements of medical equipment). In addition, even devices designed for medical treatment may suffer from deficiencies related to one or more of the following: comfort, noise, ease of use, effectiveness, size, weight, manufacturability, cost, and reliability.

[0054] One known RPT device used to treat sleep-disordered breathing is the S9 Sleep Therapy System (manufactured by ResMed Limited). Another example of an RPT device is a ventilator. Ventilators (e.g., the ResMed Stellar® series of adult and pediatric ventilators) can provide invasive and non-invasive independent respiratory support for patients for a range of conditions, including, but not limited to, NMD, OHS, and COPD.

[0055] 5.2.3.3 Humidifier Delivery of airflow without humidification can lead to dryness of the airway. When a humidifier is used with an RPT device and patient interface, humidified gas is produced, minimizing drying of the nasal mucosa and increasing comfort of the patient's airway. Additionally, in cooler climates, the application of warm air to the facial area surrounding the patient interface generally provides more comfort than cool air. [Prior art documents] [Patent documents]

[0056] [Patent Document 1] U.S. Patent No. 4,944,310 [Patent Document 2] U.S. Patent No. 6,532,959 [Patent Document 3] International Publication No. 1998 / 004310 [Patent Document 4] International Publication No. 2006 / 074513 [Patent Document 5] International Publication No. 2010 / 135785 [Patent Document 6] U.S. Patent No. 4,782,832 [Patent Document 7] International Publication No. 2004 / 073778 [Patent Document 8] US Patent Application Publication No. 2009 / 0044808 [Patent Document 9] International Publication No. 2005 / 063328 [Patent Document 10] International Publication No. 2006 / 130903 [Patent Document 11] International Publication No. 2009 / 052560 [Patent Document 12] US Patent Application Publication No. 2007 / 0246043 [Patent Document 13] U.S. Patent No. 6,044,844 [Patent Document 14] U.S. Patent No. 7,866,944 [Patent Document 15] U.S. Patent No. 8,638,014 [Patent Document 16] U.S. Patent No. 8,636,479 [Patent Document 17] International Publication No. 2013 / 020167 [Patent Document 18] U.S. Patent No. 8,733,349 [Non-patent literature]

[0057] [Non-Patent Document 1] “Respiratory Physiology”, by John B. West, Lippincott Williams & Wilkins, 9th edition published 2011 Summary of the Invention [Problem to be solved by the invention]

[0058] 6. Brief description of the technology The present technology relates to the provision of medical devices for use in the diagnosis, amelioration, treatment or prevention of respiratory disorders, which medical devices have one or more of improved comfort, cost, effectiveness, ease of use and manufacturability. [Means for solving the problem]

[0059] A first aspect of the present technology relates to devices used in the diagnosis, amelioration, treatment or prevention of respiratory disorders.

[0060] An aspect of certain forms of the present technology is to provide methods and / or devices that improve patient compliance with respiratory therapy.

[0061] One form of the present technology involves a patient interface for delivering a supply of pressurized breathable gas to an entrance of a patient's airway.

[0062] Another aspect of one form of the present technology includes a positioning and stabilizing structure for holding a seal-forming structure in a therapeutically effective position on a patient's head. The seal-forming structure may be constructed and arranged to form a seal with an area of the patient's face surrounding an entrance to the patient's airway in use to deliver a flow of air at a therapeutic pressure of at least 4 cmH2O relative to ambient air pressure throughout the patient's respiratory cycle. The positioning and stabilizing structure may include at least one gas delivery tube for delivering the flow of air through the seal-forming structure to the entrance to the patient's airway. The at least one gas delivery tube may be constructed and arranged to contact at least a region of the patient's head above the ear base in use. The positioning and stabilizing structure may include an adjustment mechanism for adjusting the length of the at least one gas delivery tube to allow the positioning and stabilizing structure to fit different sized heads. The positioning and stabilizing structure may include a biasing mechanism that applies a biasing force along at least a portion of the length of the at least one gas delivery tube in use to urge the seal-forming structure toward the entrance to the patient's airway.

[0063] Another aspect of one form of the present technology includes a patient interface including a plenum chamber pressurizable to a therapeutic pressure of at least 4 cmH2O above ambient air pressure. The plenum chamber may include a plenum chamber inlet port sized and configured to receive an airflow at the therapeutic pressure for breathing by the patient. The patient interface may include a seal-forming structure constructed and arranged to form a seal with an area of the patient's face surrounding an entrance to the patient's airways, whereby the airflow at the therapeutic pressure is delivered to at least an entrance to the patient's nares. The seal-forming structure may be constructed and arranged to maintain the therapeutic pressure within the plenum chamber throughout the patient's respiratory cycle in use. The patient interface may include a connection port that fluidly connects to an air circuit connected to the airflow in use. The connection port may be located near the top, side, or back of the patient's head in use. The patient interface may include a positioning and stabilizing structure for holding the seal-forming structure in a therapeutically effective position on the patient's head. The positioning and stabilizing structure may include at least one gas delivery tube for delivering the airflow through the seal-forming structure to the entrance of the patient's airways. The at least one gas delivery tube may be constructed and arranged to contact at least a region of the patient's head above the ear base in use. The positioning and stabilizing structure may include an adjustment mechanism for adjusting the length of the at least one gas delivery tube to allow the positioning and stabilizing structure to fit different sized heads. The positioning and stabilizing structure may include a biasing mechanism that applies a biasing force along at least a portion of the length of the at least one gas delivery tube in use to urge the seal-forming structure toward an entrance to the patient's airway.

[0064] Another aspect of one form of the present technology includes a positioning and stabilizing structure for holding a seal-forming structure in a therapeutically effective position on a patient's head. The seal-forming structure may be constructed and arranged to form a seal with an area of the patient's face surrounding an entrance to the patient's airway in use to hermetically deliver airflow at a therapeutic pressure of at least 4 cmH2O relative to ambient air pressure throughout the patient's respiratory cycle. The positioning and stabilizing structure may include at least one tie. The at least one tie may be configured to contact the patient's head in use. The at least one tie may include at least one gas delivery tube for delivering airflow through the seal-forming structure to the entrance to the patient's airway. The at least one gas delivery tube may be constructed and arranged to cover at least a region of the patient's head above the ear base in use. The positioning and stabilizing structure may include an adjustment mechanism for adjusting the at least one tie to allow the positioning and stabilizing structure to fit different sized heads. The positioning and stabilizing structure may be configured such that the adjustment mechanism is positioned out of contact with the patient's face in use.

[0065] Another aspect of one form of the present technology includes a patient interface including a plenum chamber pressurizable to a therapeutic pressure of at least 4 cmH2O above ambient air pressure. The plenum chamber may include a plenum chamber inlet port sized and configured to receive an airflow at the therapeutic pressure for breathing by the patient. The patient interface may include a seal-forming structure constructed and arranged to form a seal against an area of the patient's face surrounding an entrance to the patient's airways, whereby the airflow at the therapeutic pressure is delivered to at least an entrance to the patient's nares. The seal-forming structure may be constructed and arranged to maintain the therapeutic pressure within the plenum chamber throughout the patient's respiratory cycle in use. The patient interface may include a connection port that fluidly connects to an air circuit connected to the airflow in use. The connection port may be located near the top, side, or back of the patient's head in use. The patient interface may include a positioning and stabilizing structure for holding the seal-forming structure in a therapeutically effective position on the patient's head. The positioning and stabilizing structure may include at least one tie. The at least one tie may be configured to contact the patient's head in use. The at least one tie may include at least one gas delivery tube for delivering airflow through the seal-forming structure to an entrance to the patient's airway. The at least one gas delivery tube may be constructed and arranged to cover at least a region of the patient's head above the ear base in use. The positioning and stabilizing structure may include an adjustment mechanism for adjusting the at least one tie to allow the positioning and stabilizing structure to fit different sized heads. The positioning and stabilizing structure may be configured such that the adjustment mechanism is positioned to avoid contact with the patient's face in use.

[0066] Another aspect of one form of the present technology includes a patient interface including a plenum chamber pressurizable to a therapeutic pressure of at least 4 cmH2O above ambient air pressure. The plenum chamber may include a plenum chamber inlet port sized and configured to receive an airflow at the therapeutic pressure for breathing by the patient. The patient interface may include a seal-forming structure constructed and arranged to form a seal with an area of the patient's face surrounding an entrance to the patient's airway, whereby the airflow at the therapeutic pressure is delivered to at least an entrance to the patient's nares. The seal-forming structure may be constructed and arranged to maintain the therapeutic pressure within the plenum chamber throughout the patient's respiratory cycle in use. The patient interface may include a positioning and stabilizing structure for holding the seal-forming structure in a therapeutically effective position on the patient's head. The positioning and stabilizing structure may include a first tube portion constructed and arranged to cover an area of the patient's head above the supra-ear point in use. The positioning and stabilizing structure may include a tie portion that rests on or covers the posterior part of the occipital bone of the patient's head in use. The patient interface may include a vent structure for allowing continuous flow of gas exhaled by the patient from within the plenum chamber to the surroundings. The vent structure is sized and shaped to maintain therapeutic pressure within the plenum chamber during use. The first tube may be configured to conduct at least a portion of the airflow breathed by the patient. The first tube may be configured to be taut during use. The first tube may include a length adjustment mechanism.

[0067] Another aspect of one form of the present technology includes a positioning and stabilizing structure for holding a seal-forming structure in a therapeutically effective position on a patient's head. The seal-forming structure may be constructed and arranged to form a seal with an area of the patient's face surrounding an entrance to the patient's airway in use to hermetically deliver airflow at a therapeutic pressure of at least 4 cmH2O relative to ambient air pressure throughout the patient's respiratory cycle. The positioning and stabilizing structure may include a first conduit portion constructed and arranged to cover an area of the patient's head above the supra-ear point in use. The positioning and stabilizing structure may include a tie portion that rests on or covers the rear of the occipital bone of the patient's head in use. The first conduit portion may be configured to conduct at least a portion of the airflow breathed by the patient. The first conduit portion may be configured to be taut in use. The first conduit portion may include a length adjustment mechanism.

[0068] Another aspect of one form of the present technology includes a patient interface including a plenum chamber pressurizable to a therapeutic pressure of at least 4 cmH2O above ambient air pressure. The plenum chamber may include a plenum chamber inlet port sized and configured to receive an airflow at the therapeutic pressure for breathing by the patient. The patient interface may include a seal-forming structure constructed and arranged to form a seal with an area of the patient's face surrounding an entrance to the patient's airways, whereby the airflow at the therapeutic pressure is delivered to at least an entrance to the patient's nares. The seal-forming structure may be constructed and arranged to maintain the therapeutic pressure within the plenum chamber throughout the patient's respiratory cycle in use. The patient interface may include a positioning and stabilizing structure that provides a resilient force to hold the seal-forming structure in a therapeutically effective position on the patient's head for sealingly delivering the therapeutic pressure in the airflow. The positioning and stabilizing structure may include a tie. The tie may be constructed and arranged such that at least a portion of the tie covers an area of the patient's head above the supra-ear point in use. The tie may include an adjustable-length gas delivery tube for delivering an air flow through the seal-forming structure to an entrance to the patient's airway. The gas delivery tube may be configured to contact a portion of the patient's head in use. The positioning and stabilizing structure may include a biasing mechanism that applies a biasing force to the adjustable-length gas delivery tube to urge the seal-forming structure toward the entrance to the patient's airway in use.

[0069] Another aspect of one form of the present technology includes a positioning and stabilizing structure for holding a seal-forming structure in a therapeutically effective position on a patient's head. The seal-forming structure may be constructed and arranged to form a seal with an area of the patient's face surrounding an entrance to the patient's airway in use to deliver airflow at a therapeutic pressure of at least 4 cmH2O relative to ambient air pressure throughout the patient's respiratory cycle. The positioning and stabilizing structure may include a tie. The tie may be constructed and arranged such that at least a portion of the tie covers an area of the patient's head above the supra-ear point in use. The tie may include an adjustable-length gas delivery tube for delivering airflow through the seal-forming structure to the entrance to the patient's airway. The gas delivery tube may be configured to contact a portion of the patient's head in use. The positioning and stabilizing structure may include a biasing mechanism that applies a biasing force to the adjustable-length gas delivery tube to urge the seal-forming structure toward the entrance to the patient's airway in use.

[0070] Another aspect of one form of the present technology includes an inflatable positioning and stabilizing structure for sealingly delivering an airflow at a continuously positive pressure relative to ambient air pressure to an entrance to a patient's airway formed by a seal-forming structure of a patient interface, configured to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure throughout the patient's respiratory cycle while the patient is sleeping, thereby improving sleep-disordered breathing. The positioning and stabilizing structure may include at least one gas delivery tube for delivering the airflow to the entrance of the patient's airway through the seal-forming structure. The positioning and stabilizing structure may also include an adjustment mechanism that allows for dimensional adjustment of the positioning and stabilizing structure. The positioning and stabilizing structure may also include a biasing mechanism that applies a biasing force to the adjustment mechanism and the advancing seal-forming structure to move it toward the entrance of the patient's airway.

[0071] Another aspect of one form of the present technology includes a patient interface for delivering a supply of pressurized air at a continuous positive pressure relative to ambient air pressure to an entrance of a patient's airways. The patient interface is configured, in use, to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure throughout the patient's respiratory cycle while the patient is sleeping, to improve sleep-disordered breathing. The patient interface may include a connection port for fluid connection to an air circuit connected to the supply of pressurized air in use. The connection port may be positioned near the top, side, or back of the patient's head in use. The patient interface may also include a seal-forming structure that seals an area surrounding an entrance to the patient's airways. The patient interface may also include an inflatable positioning and stabilizing structure for maintaining a seal formed by the seal-forming structure. The positioning and stabilizing structure may include at least one gas delivery tube for delivering a flow of air through the seal-forming structure to the entrance of the patient's airways.

[0072] Another aspect of a related form of the present technology includes a patient interface that includes a positioning and stabilizing structure that includes an adjustment mechanism to allow for dimensional adjustment of the positioning and stabilizing structure.

[0073] Another aspect of a related form of the present technology includes a patient interface that includes a biasing mechanism for applying a biasing force to the adjustment mechanism to urge the seal-forming structure toward the entrance of the patient's airway.

[0074] Another aspect of one form of the present technology includes an inflatable positioning and stabilizing structure for sealingly delivering an airflow at a continuous positive pressure relative to ambient air pressure to an entrance to a patient's airway formed by a seal-forming structure of a patient interface, and configured to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure throughout the patient's respiratory cycle while the patient is sleeping, thereby improving sleep-disordered breathing. The positioning and stabilizing structure may include at least one gas delivery tube for delivering the airflow to the entrance to the patient's airway through the seal-forming structure. The positioning and stabilizing structure may also include an adjustment mechanism that allows for dimensional adjustment of the positioning and stabilizing structure. The positioning and stabilizing structure may be configured such that the adjustment mechanism does not contact the patient's cheek region during use.

[0075] Another aspect of one form of the present technology includes a patient interface for delivering a supply of pressurized air at a continuous positive pressure relative to ambient air pressure to an entrance of a patient's airways. The patient interface is configured, in use, to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure throughout the patient's respiratory cycle while the patient is sleeping, to improve sleep-disordered breathing. The patient interface may include a positioning and stabilizing structure. The positioning and stabilizing structure may include at least one gas delivery tube for delivering a flow of air to the entrance of the patient's airways through the seal-forming structure. The positioning and stabilizing structure may also include an adjustment mechanism that allows for dimensional adjustment of the positioning and stabilizing structure. The positioning and stabilizing structure may be configured such that, in use, the adjustment mechanism is positioned so as not to contact the patient's cheek region.

[0076] Another aspect of certain forms of the present technology is a system for treating a respiratory disorder, the system including a patient interface according to any one or more of the other aspects of the present technology, an air circuit, and a source of air at positive pressure.

[0077] Another aspect of one form of the present technology is a patient interface that is molded or otherwise constructed with a peripheral shape that is complimentary to the shape of the intended wearer.

[0078] Another aspect of certain forms of the present technology is a patient interface that includes a seal-forming structure configured to expose the patient's oral cavity in use.

[0079] Another aspect of certain forms of the present technology is a patient interface that includes a seal-forming structure configured to prevent any portion of the seal-forming structure from entering the oral cavity during use.

[0080] Another aspect of certain forms of the present technology is a patient interface that includes a seal-forming structure configured to prevent the seal-forming structure from extending into the patient's airway.

[0081] Another aspect of certain forms of the present technology is a patient interface that includes a seal-forming structure configured such that, in use, the seal-forming structure does not extend below the mental protuberance area.

[0082] Another aspect of certain forms of the present technology is a patient interface constructed and arranged to expose the patient's eye during use.

[0083] Another aspect of certain forms of the present technology is a patient interface constructed and arranged to allow the patient to breathe ambient air in the event of a power outage.

[0084] Another aspect of certain forms of the present technology is a patient interface that includes a seal-forming structure configured to form a seal on the underside of the patient's nose without contacting the nose bridge region of the patient's nose.

[0085] Another aspect of certain forms of the present technology is a patient interface that includes a vent and a plenum chamber, the patient interface constructed and arranged to allow gas from within the plenum chamber to travel through the vent to the ambient.

[0086] Another aspect of certain forms of the present technology is a patient interface that is constructed and arranged to allow the patient to lie comfortably in a side or lateral sleeping position when using the patient interface.

[0087] Another aspect of certain forms of the present technology is a patient interface that is constructed and arranged to allow the patient to lie comfortably in a supine sleep position when using the patient interface.

[0088] Another aspect of certain forms of the present technology is a patient interface that is constructed and arranged to allow the patient to lie comfortably in a prone sleeping position when using the patient interface.

[0089] One aspect of certain forms of the present technology is a medical device that is easy to use, for example, by individuals without medical training, individuals with limited dexterity or acumen, or individuals with limited experience using such medical devices.

[0090] An aspect of one form of the present technology is a patient interface that can be cleaned at the patient's home, for example with soapy water, without the need for special cleaning equipment.An aspect of one form of the present technology is a humidifier tank that can be cleaned at the patient's home, for example with soapy water, without the need for special cleaning equipment.

[0091] Of course, some of the above aspects may form sub-aspects of the present technology, and various sub-aspects and / or aspects may be combined in various ways to form further aspects or sub-aspects of the present technology.

[0092] Other features of the present technology will become apparent in light of the information contained in the following detailed description, abstract, drawings, and claims.

[0093] 7 Brief description of the drawings The present technology is illustrated by way of example and not limitation in the accompanying drawings, in which like reference numerals include like elements: [Brief explanation of the drawings]

[0094] [Figure 1A] FIG. 1 shows a system including a patient 1000 wearing a patient interface 3000. The system takes the form of nasal pillows and receives air at positive pressure supplied by an RPT device 4000. The air from the RPT device 4000 is humidified by a humidifier 5000 and travels along an air circuit 4170 to the patient 1000. A bed companion 1100 is also shown. [Figure 1B] Figure 4 shows a system including a patient 1000 wearing a patient interface 3000. The system takes the form of a nasal mask and receives air at positive pressure supplied by an RPT device 4000. The air from the RPT device is humidified by a humidifier 5000 and travels along an air circuit 4170 to the patient 1000. [Figure 1C] FIG. 3 shows a system including a patient 1000 wearing a patient interface 3000. The patient interface 3000 takes the form of a full face mask and receives a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified by a humidifier 5000 and travels along an air circuit 4170 to the patient 1000. [Figure 2A] An outline of the human respiratory system including the nasal and oral cavities, larynx, vocal folds, esophagus, trachea, bronchi, lungs, alveolar sacs, heart and diaphragm. [Figure 2B] FIG. 2B is a diagram of the human upper respiratory tract, including the nasal cavity, nasal bones, lateral nasal cartilages, greater alar cartilages, nostrils, upper lip, lower lip, larynx, hard palate, soft palate, oropharynx, tongue, epiglottis, vocal folds, esophagus, and trachea. [Figure 2C] A front view of the face including several features of the surface anatomy including upper lip, vermilion, lower lip, mouth width, medial canthus, alae of the nose, nasolabial folds, and corners of the mouth. The superior, inferior, radially inward, and radially outward directions are also indicated. [Figure 2D] A lateral view of the head including several features of the surface anatomy, including the glabella, serrion, nasal tip, subnasal point, upper lip, lower lip, supramenton, nasal ridge, alar crest, supra- and sub-auricular points. The directions of superior and inferior, anterior and posterior are also indicated. [Figure 2E]

[0023] Figure 1 is a further lateral view of the head, showing the approximate locations of the Frankfort horizontal and nasolabial angle. The coronal view is also shown. [Figure 2F] A bottom view of the nose including several features including the nasolabial fold, lower lip, upper lip vermilion, nostrils, subnasal point, columella, nasal tip, major axis of the nostril and sagittal plane. [Figure 3A] FIG. 33 shows a patient interface 3000 including a positioning and stabilizing structure 3300 in accordance with a particular form of the present technology. [Figure 3B] FIG. 33 shows a patient interface 3000 including a positioning and stabilizing structure 3300 in accordance with a particular form of the present technology. [Figure 3C] FIG. 33 shows a patient interface 3000 including a positioning and stabilizing structure 3300 in accordance with a particular form of the present technology. [Figure 3D] FIG. 33 shows a patient interface 3000 including a positioning and stabilizing structure 3300 in accordance with a particular form of the present technology. [Figure 3E] FIG. 33 shows a patient interface 3000 including a positioning and stabilizing structure 3300 in accordance with a particular form of the present technology. [Figure 3F] FIG. 3C is a plan view of the patient interface 3000 shown in FIGS. 3C, 3D, and 3E. [Figure 3G] FIG. 3F is a cross-sectional view of a portion of the patient interface 3000 shown in FIG. 3F. [Figure 3H]FIG. 13 shows a longitudinal cross section of the headgear tube 3350 of the patient interface 3000. [Figure 3I] 13 is a graph showing a plot of an exemplary force extension characteristic of the headgear tube 3350 of the patient interface 3000. [Figure 3J] 3C, 3D, and 3E are side views of the patient interface as worn by a patient, with the connection port 3600 in a center position (in phantom), a front position, and a rear position. [Figure 3K] 3C, 3D, and 3E are side views showing the patient interface as worn by a patient of one head size and as worn (in phantom) by a patient of a larger head size. [Figure 3L] FIG. 3D is a side view of the patient interface shown in FIGS. 3C, 3D, and 3E being worn by a patient, with adjustment mechanisms 3360 positioned in the center, anteriorly, and posteriorly (in phantom). [Figure 4A] FIG. 14 shows a cushion assembly 3150 of a patient interface 3000 in accordance with certain forms of the present technology. [Figure 4B] FIG. 14 shows a cushion assembly 3150 of a patient interface 3000 in accordance with certain forms of the present technology. [Figure 4C] FIG. 14 shows a cushion assembly 3150 of a patient interface 3000 in accordance with certain forms of the present technology. [Figure 4D] FIG. 14 shows a cushion assembly 3150 of a patient interface 3000 in accordance with certain forms of the present technology. [Figure 4E] FIG. 14 shows a cushion assembly 3150 of a patient interface 3000 in accordance with certain forms of the present technology. [Figure 5] FIG. 30 shows a patient interface 3000 including a positioning and stabilizing structure 3300 having a fold 3364 and a strap 3390 in accordance with one form of the present technology. [Figure 5A]5, where the rotating fold 3366 is folded onto an adjacent tube 3368 to a different level. [Figure 5B] 5, where the rotating fold 3366 is folded onto an adjacent tube 3368 to a different level. [Figure 6] FIG. 30 shows a patient interface 3000 including a positioning and stabilizing structure 3300 including a flexible tube 3350 in accordance with one form of the present technology. [Figure 7A] FIG. 33 shows a patient interface 3000 including a positioning and stabilizing structure 3300 having a first tube 3370 and a second tube 3372 in accordance with a certain form of the present technology. [Figure 7B] FIG. 33 shows a patient interface 3000 including a positioning and stabilizing structure 3300 having a first tube 3370 and a second tube 3372 in accordance with a certain form of the present technology. [Figure 7C] FIG. 33 shows a patient interface 3000 including a positioning and stabilizing structure 3300 having a first tube 3370 and a second tube 3372 in accordance with a certain form of the present technology. [Figure 8] FIG. 33 shows a portion of a patient interface 3000 including a positioning and stabilizing structure 3300 having separately adjustable first and second tube portions 3370, 3372 in accordance with one form of the present technology. [Figure 9] FIG. 33 shows a portion of a patient interface including a positioning and stabilizing structure 3300 having a first tube portion 3370 and a second tube portion 3372 in accordance with one form of the present technology. [Figure 10A] FIG. 30 shows a patient interface 3000 including a positioning and stabilizing structure 3300 having an adjustment mechanism 3360 in accordance with one form of the present technology. [Figure 10B] FIG. 30 shows a patient interface 3000 including a positioning and stabilizing structure 3300 having threaded tubes 3380 and 3382 in accordance with one form of the present technology. [Figure 11] FIG. 30 shows a patient interface 3000 including a positioning and stabilizing structure 3300 having interchangeable tube sections 3385 and 3386 in accordance with one form of the present technology. [Figure 12] FIG. 30 shows a patient interface 3000 including a positioning and stabilizing structure 3300 having an insertable tube 3387 in accordance with one form of the present technology. [Figure 13] FIG. 33 shows a portion of a tube 3350 for a patient interface including an expandable tube section 3355 in accordance with one form of the present technology. [Figure 14] FIG. 30 shows a patient interface 3000 including a positioning and stabilizing structure 3300 having a band 3395 in accordance with one form of the present technology. [Figure 15] FIG. 34 shows a portion of a patient interface including interchangeable loop inserts 3410 and 3411 in accordance with one form of the present technology. [Figure 16]

[0043] FIG. 34 shows a portion of a patient interface including an inflatable loop insert member 3420 in accordance with one form of the present technology. [Figure 17] FIG. 30 shows a patient interface 3000 including a positioning and stabilizing structure 3300 having a corrugated tube 3362 and an elastic sleeve 3340 in accordance with one form of the present technology. [Figure 18] FIG. 1 illustrates an RPT device in accordance with one form of the present technology. [Figure 19A] FIG. 10 is an isometric view of a humidifier in accordance with one form of the present technology. [Figure 19B] FIG. 10 is an isometric view of a humidifier in accordance with one form of the present technology, showing the humidifier reservoir 5110 removed from the humidifier reservoir dock 5130. DETAILED DESCRIPTION OF THE INVENTION

[0095] 8 Detailed Description of the Embodiments of the Present Technology Before describing the present technology in further detail, it is to be understood that the present technology is not limited to the specific embodiments described herein, which may vary. It is also to be understood that the terminology used in the present disclosure is for the purpose of describing the specific embodiments described herein, and is not intended to be limiting.

[0096] The following description is provided in connection with various embodiments that may share one or more common characteristics and / or features. It should be understood that one or more features of any one embodiment may be combined with one or more features of another embodiment or other embodiments. In addition, any single feature or combination of features in any of these embodiments may constitute an additional embodiment.

[0097] 8.1 Treatment In one form, as shown in Figure 1A, the present technology includes a method of treating a respiratory disorder, the method including applying positive pressure to the entrance of the airways of a patient 1000.

[0098] 8.2 Treatment Systems In one form, the present technology includes an apparatus or device for the treatment of disordered breathing. The apparatus or device may include an RPT device 4000 that supplies pressurized air to the patient 1000 via an air circuit 4170 to a patient interface 3000. The treatment systems shown in Figures 1A, 1B, and 1C use different forms of patient interface 3000.

[0099] 8.3 Patient Interface 3A, a non-invasive patient interface 3000 in accordance with one aspect of the present technology includes the following functionalities: a cushion assembly 3150, a positioning and stabilizing structure 3300, and a connection port 3600 for connection to an air circuit 4170. In some forms, the functionalities may be provided by one or more physical components. In some forms, one physical component may provide one or more functionalities.

[0100] The cushion assembly 3150 includes a seal-forming structure 3100 and a plenum chamber 3200. In use, the plenum chamber 3200 receives a supply of air at positive pressure from the air circuit 4170, and the seal-forming structure 3100 is arranged to seal an area around an entrance to the patient's airways to facilitate the supply of air at positive pressure to the airways.

[0101] 8.3.1 Seal formation structure In one form of the present technology, a seal-forming structure 3100 provides a seal-forming surface and may further provide a cushioning function.

[0102] A seal-forming structure 3100 according to the present technology may be constructed from a soft, flexible and resilient material (eg, silicone).

[0103] The seal-forming structure 3100 may be non-invasive (i.e., does not extend into the patient's airway). In some forms of the present technology, no part of the seal-forming structure 3100 enters the patient's mouth when in use. In some forms of the present technology, the seal-forming structure 3100 is configured to leave the patient's mouth exposed when in use. In some forms of the present technology, the seal-forming structure 3100 does not cover the patient's eyes when in use.

[0104] In one form, the seal-forming structure 3100 includes a sealing flange and a support flange. The sealing flange includes a relatively thin member having a thickness of less than about 1 mm (e.g., about 0.25 mm to about 0.45 mm) that extends around the peripheral length of the plenum chamber 3200. The support flange may be relatively thicker than the sealing flange. The support flange is disposed between the sealing flange and the peripheral edge of the plenum chamber 3200 and extends around at least a portion of the peripheral length. The support flange is or includes a spring-like element that functions to support the sealing flange against buckling during use. In use, the sealing flange can readily respond to system pressure in the plenum chamber 3200 by acting on its underside to form a tight sealing engagement with a surface.

[0105] In one form, shown in Figure 1A, the seal-forming portion of the non-invasive patient interface 3000 includes a pair of nasal puffs or nasal pillows, each constructed and arranged to form a seal with a respective nostril of the patient's nose. The nasal pillows patient interface 3000 is also shown in Figure 3A.

[0106] Nasal pillows according to one aspect of the present technology include a truncated cone. At least a portion of the truncated cone forms a seal over the underside of the patient's nose, the stem, and a flexible region on the underside of the truncated cone, connecting the truncated cone to the stem. Additionally, the structure to which the nasal pillows of the present technology are connected includes a flexible region adjacent to the base of the stem. The flexible region can function to facilitate a universal joint structure. The universal joint structure accommodates both the displacement and angle of the truncated cone and the relative movement of the structure to which the nasal pillows are connected. For example, the truncated cone can be displaced axially toward the structure to which the stem is connected.

[0107] In one form, the non-invasive patient interface 3000 includes a seal-forming portion that, in use, forms a seal over the upper lip region (i.e., upper lip), nose bridge region, and cheek region of the patient's face, such as the patient interface 3000 shown in FIG. 1B. This seal-forming portion delivers an air supply or breathable gas to both nares of the patient 1000 through a single orifice. This type of seal-forming structure may also be referred to as a "nasal cushion" or "nasal mask."

[0108] In another form, the seal-forming structure is configured to form a seal with the underside of the nose around the nostrils and optionally the upper lip in use. This type of seal-forming structure may also be referred to as a "nasal cradle cushion" or "sub-nasal mask." The shape of the seal-forming structure may be configured to conform to or closely follow the underside of the patient's nose (i.e., the profile and angle of the seal-forming structure may be substantially parallel to the patient's nasal-labial angle). In one form of a nasal cradle cushion, the seal-forming structure includes a septum member defining two orifices. Each of these two orifices supplies air or breathable gas to a different one of the patient's nares in use. The septum member may be configured to contact or seal against the bridge of the patient's nose in use. In some forms of the present technology, the seal-forming structure 3100 is configured to form a seal with the underside of the patient's nose without contacting the nose bridge region of the patient's nose.

[0109] In one form, the non-invasive patient interface 3000 includes a seal-forming portion that forms a seal over the chin, nose bridge, and cheek areas of the patient's face, such as the patient interface 3000 shown in Figure 1C. This seal-forming portion delivers an air supply or breathable gas to both nostrils and the oral cavity of the patient 1000 through a single orifice. This type of seal-forming structure may also be referred to as a "full face mask."

[0110] In another form, the non-invasive patient interface 3000 includes a nasal seal-forming structure 3170 and an oral seal-forming structure 3180. The nasal seal-forming structure 3170 takes the form of a nasal cushion or nasal cradle cushion, and the oral seal-forming structure 3180 is configured to form a seal around the patient's oral cavity in use (this may also be referred to as an "oral cushion" or "oral mask"). In such a mask, air or breathable material is supplied to the patient's nares and the patient's oral cavity through separate orifices in use. This type of seal-forming structure 3100 may be referred to as an "oral-nasal mask." In one form, the nasal seal-forming structure 3170 and the oral seal-forming structure 3180 are integrally formed as a single component. This is the case, for example, with the cushion assembly 3150 shown in FIGS. 4A, 4B, and 4C. Alternatively, the nasal seal-forming structure 3170 and the oral seal-forming structure 3180 may be formed separately and configured to be attached together directly or indirectly, for example, by interconnecting frames attached to each cushion. For example, the nasal seal-forming structure 3170 and the oral seal-forming structure 3180 may be configured to be modularly detached and reattached, allowing the patient interface to be functionally converted from an oronasal mask to a nasal or sub-nasal mask, or vice versa, as desired by the patient and / or physician. This is true, for example, for the cushion assembly 3150 shown in Figures 4D and 4E.

[0111] In some forms of the present technology, the seal-forming structure 3100 is configured such that, in use, the seal-forming structure does not extend below the mental protuberance area of the patient's head.

[0112] Unless otherwise specified, embodiments of patient interfaces according to the present technology may include any of the above types of seal-forming structures.

[0113] In certain forms of the present technology, the seal-forming structure 3100 is configured to accommodate a particular size and / or shape of facial head. For example, one form of the seal-forming structure 3100 is suitable for large sized heads but not for small sized heads. In another example, one form of the seal-forming structure 3100 is suitable for small sized heads but not for large sized heads.

[0114] 8.3.2 Plenum chamber The plenum chamber 3200, in use, receives pressurized breathable gas and is pressurized to a pressure above ambient pressure. In some forms of the present technology, the plenum chamber 3200 has an edge 3210 shaped to be complimentary to the surface contours of an average human face in the area where a seal is formed in use. In use, the peripheral edge of the plenum chamber 3200 is positioned in close proximity to the adjacent surface of the face. Actual contact with the face is provided by the seal-forming structure 3100. The seal-forming structure 3100 may extend around the entire edge of the plenum chamber 3200 in use.

[0115] The plenum chamber 3200 may receive pressurized breathable gas through a plenum chamber inlet port sized and configured to receive gas from another portion of the patient interface 3000.

[0116] 8.3.3 Positioning and stabilizing structures The seal-forming structure 3100 of the patient interface 3000 of the present technology may be held in a sealed position in use by the positioning and stabilizing structure 3300. The positioning and stabilizing structure 3300 may also be referred to as "headgear" as it engages the patient's head to hold the patient interface 3000 in a sealed position.

[0117] In one form of the present technology, there is provided a positioning and stabilizing structure 3300 configured to be worn by a patient while sleeping, in one example, the positioning and stabilizing structure 3300 has a low profile or cross-sectional thickness to reduce the perceived or actual bulk of the device.

[0118] The positioning and stabilizing structure 3300 may include at least one tie. A tie may be understood as a structure designed to resist tension. In use, the tie is the portion of the positioning and stabilizing structure 3300 that is under tension. Some ties add elasticity resulting from this tension, as described above. The tie may function to maintain the seal-forming structure 3100 in a therapeutically effective position on the patient's head. In certain forms of the present technology, the positioning and stabilizing structure 3300 may include ties in the form of headgear tubes 3350 and / or headgear straps, as described below.

[0119] 8.3.3.1 Headgear tubing 3A , the positioning and stabilising structure 3300 includes at least one tube 3350 that delivers pressurised air received from a conduit forming part of the air circuit 4170 from the RPT device to the patient's airways, for example through the plenum chamber 3200 and the seal-forming structure 3100. These tubes 3350 are an integral part of the headgear 3300 of the patient interface 3000 for positioning and stabilising the seal-forming structure 3100 of the patient interface to an appropriate portion of the patient's face (e.g. the nose and / or mouth). As a result, the conduit of the air circuit 4170 providing the pressurised air flow can be connected to the connection port 3600 of the patient interface in a location other than in front of the patient's face, which may be obscured by some people.

[0120] The positioning and stabilizing structure 3300 may be described as inflatable because it is capable of containing and moving air through the tube 3350 for delivery of pressurized air from the air circuit 4170 to the patient's airway. It is understood that an inflatable positioning and stabilizing structure 3300 does not require all components of the positioning and stabilizing structure 3300 to be inflatable.

[0121] In certain forms of the present technology, the patient interface 3000 may include a connection port 3600 located near the top, side, or back of the patient's head. For example, in the form of the present technology shown in FIG. 3A, the connection port 3600 is located on top of the patient's head. Patient interfaces where the connection port is not located in front of the patient's face may be advantageous, as some patients may find it unsightly and uncomfortable when a conduit is connected to a front-of-face patient interface. For example, a conduit connecting to a front-of-face patient interface may be prone to becoming tangled with bedding or bed linens, especially if the conduit extends downward from the patient interface during use. Forms of the present technology that use patient interfaces with a connection port located near the top of the patient's head during use may make it easier or more comfortable for the patient to lie or sleep in one or more of the following positions: a lateral or horizontal position, a supine position (i.e., face up), and a prone position (i.e., face down). Additionally, connecting the conduit to the front of the patient interface can lead to a problem known as tube drag, in which the conduit can create an undesirable pulling force on the patient interface, causing it to be pulled down and away from the face.

[0122] In the example of FIG. 3A, at least one tube 3350 extends from the connection port 3600 on the patient's cheek area and on the patient's ear between the cushion assembly 3150 (i.e., between the portion of the tube 3350 that connects to the cushion assembly 3150 that covers the maxillary area of the patient's head in use, and the portion of the tube 3350 that covers the area of the patient's head above the supra-ear point on the patient's head).

[0123] In the form of the technology shown in FIG. 3A, the positioning and stabilizing structure 3300 includes two tubes 3350. In use, each tube is positioned on a different side of the patient's head and extends through each cheek area from above each ear (above the supra-ear point on the patient's head) to a connection port 3600 on the top of the patient's head. This form of technology can be advantageous because if the patient is lying on their side and one of the tubes is compressed, blocking or partially blocking gas flow along that tube, the other tube remains open and can still provide pressurized gas to the patient. In other embodiments of the technology, the patient interface can include a different number of tubes (e.g., one tube or three or more tubes). In one example where the patient interface has one tube 3350, the single tube 3350 is placed on one side of the patient's head (e.g., over one cheek area) during use, and the strap forms part of the positioning and stabilizing structure 3300 and is placed on the other side of the patient's head (e.g., over the other area) during use to help secure the patient interface 3000 on the patient's head.

[0124] 3A, the two tubes 3350 are fluidly connected to each other at their upper ends and to a connection port 3600. In one embodiment, the two tubes are integrally formed, while in other embodiments the tubes are separate components that may be interconnected during use and disconnected, for example for cleaning or storage. If separate tubes are used, the tubes may be indirectly connected to each other, for example, to a T-shaped conduit having two conduit arms each fluidly connectable to the tubes 3350 and a third conduit arm or opening which acts as the connection port 3600 and which is connectable to the air circuit 4170 during use.

[0125] The tubes 3350 may be formed from a semi-rigid material, such as an elastomeric material (e.g., silicone). The tubes may have a natural preformed shape or may bend or move to assume another shape when a force is applied to the tube. For example, the tubes may generally assume an arc or curved shape that resembles the contours of the patient's head between the top of the head and the nose or mouth area.

[0126] 3A has tubes 3350 that curve around the top of the patient's head from the top of the tube 3350 where it connects to a connection port 3600 on the top of the head to the point where the rear headgear straps 3310 connect to the tube 3350 without any sagittal curvature. Between the point where the rear headgear straps 3310 connect to the tube 3350 and the bottom end of the tube 3350 where it connects to the cushion assembly 3150 in front of the patient's airway below the nose, the tube 3350 curves forward across the cheek area between the patient's ears and eyes. The radius of the curve in this portion of the tube 3350 can be in the range of 60-100 mm, for example, 70-90 mm (e.g., 80 mm). The lower end of the tube 3350 and the point where the rear headgear straps 3310 connect to the tube 3350 may be at an angle ranging from 65 to 90 degrees (eg, 75 to 80 degrees).

[0127] 3350。

[00107] In certain forms of the present technology, one or more sections of the tube 3350 may be stiffened with one or more stiffening or stiffening elements. Examples of stiffening elements include: a relatively thicker-walled section of the tube 3350, a section of the tube 3350 made from a relatively stiffer material than the material making up the other sections of the tube, and stiffening members attached to or embedded in the interior, exterior, or interior of a portion of the tube. The use of such stiffening elements helps control how the positioning and stabilizing structure 3300 functions during use (e.g., when the tube 3350 is likely to deform when a force is applied to it, when the tube 3350 is likely to maintain its shape when a force is applied to it). Selecting where such stiffening elements are placed within the tube 3350 can help promote comfort when wearing the patient interface 3000 and can help the seal-forming structure maintain a good seal during use. Stiffening or stiffening elements can be placed within the positioning and stabilizing structure 3300. The positioning and stabilizing structure 3300 is configured to support a relatively heavy seal-forming structure (eg, a full face or oral-nasal cushion assembly).

[0128] The length of the tube 3350 in the form of the present technology shown in FIG. 3A is 15-30 cm (e.g., 20-27 cm). In one embodiment, the length of the tube is 25 cm. The length of the tube is selected to suit the dimensions of a typical patient's head (e.g., the distance between the area near the top of the head where the upper end of the tube 3350 is located as it follows a generally arcuate path extending down the side of the head and over the patient's cheek area, to the area near the opening to the patient's airway where the lower end of the tube 3350 connects to the cushion assembly 3150, as shown in FIG. 3A). As described in more detail below, the patient interface 3000 is configured such that the length of the tube 3350 in some forms of the present technology can be varied and the length can apply to the tube in a retracted, extended, or neutral state. It will be understood that the length of the tube 3350 will depend on the lengths of other components in the patient interface 3000 (e.g., the arm length of a T-shaped conduit to which the upper end of the tube 3350 is connected).

[0129] The level of fit of the patient interface 3000 to an individual patient can be changed by changing the length of the tube 3350, or alternatively or additionally, by changing the position of the patient interface 3000 on the patient's head. For example, by moving the positioning and stabilizing structure 3300 in a posterior or anterior direction on the patient's head, a patient interface 3000 having a particular length of tube 3350 can be adjusted to better fit the patient. Positioning the connection port 3600 further forward (i.e., in an anterior direction) allows the patient interface 3000 having a particular length of tube 3350 to fit larger heads than if the connection port 3600 was positioned further back (i.e., in a posterior direction).

[0130] In certain forms of the present technology, the patient interface 3000 is configured so that the connection port 3600 can be positioned at a range of locations across the top of the patient's head, allowing the patient interface 3000 to be positioned to suit the comfort or fit of an individual patient. One way this can be achieved so that the cushion assembly 3150 forms an effective seal with the patient's face regardless of the location of the connection port 3600 on the patient's head is by decoupling the movement of the upper part of the patient interface 3000 from the lower part of the patient interface 3000. Such decoupling can be achieved, for example, using a mechanism that allows parts of the headgear tube 3350 to easily move or flex relative to other parts of the patient interface 3000. Such mechanisms are described below.

[0131] In certain forms of the present technology, the patient interface 3000 is configured so that the connection port 3600 is generally located at the top of the patient's head. The connection port 3600 may be located in the sagittal plane and aligned with the ear-base point in a plane parallel to the coronal plane. The ear-base point is shown in FIG. 2D. As described below, in some forms of the present technology, the headgear 3300 is configured to be worn in different positions, i.e., the connection port 3600 may be located near the top of the patient's head in the sagittal plane up to around 20 mm anterior or posterior to the ear-base point.

[0132] The cross-sectional shape of the tube 3350 can be circular, elliptical, oval, D-shaped, or rounded rectangular, for example, as described in U.S. Patent Application Publication No. 2007 / 0129994, which is incorporated herein by reference. Cross-sectional shapes that present a flat surface of the tube on the side that faces and contacts other parts of the patient's face or head may be more comfortable to wear than, for example, a tube with a circular cross-section.

[0133] The cross-sectional width and / or height of the tube 3350 can be 8 to 25 mm (e.g., 10 to 20 mm). In some configurations where the tube has a D-shaped cross-section, such as the longitudinal cross-section of the headgear tubing 3350 shown in FIG. 3H, the width of the tube is 15 to 25 mm (e.g., 20 mm) and the height is 8 to 15 mm (e.g., 10 mm). The height can be considered the dimension of the tube away from the patient's face (i.e., the distance between the patient-contacting side 3348 and the outermost portion of the non-patient-contacting side 3349), and the width can be considered the dimension across the surface of the patient's head. The cross-sectional thickness of the material forming the tube 3350 can be 0.8 to 1.6 mm (e.g., 1.0 to 1.5 mm, e.g., 1.3 mm).

[0134] The D-shaped cross-section tube 3350 shown in Figure 3H has a curved edge 3347 located on the side 3348 that contacts the patient. The curved edge that is in contact with or adjacent to the patient's skin helps to increase comfort when wearing the patient interface 3000 and to avoid marking or irritation on the patient's skin. The D-shaped cross-sectional profile of the tube also makes it more resistant to buckling than other shaped profiles.

[0135] As described in U.S. Patent No. 6,255,999, the tube 3350 may also be crush resistant to prevent the flow of breathable gas through the tube if it is crushed during use (e.g., if it is crushed between the patient's face and a pillow). A crush resistant tube is not necessary in all cases, as the pressurized gas in the tube may act as a splint to prevent or at least limit collapse of the tube 3350 during use. Using a crush resistant tube may be advantageous when only a single tube 3350 is present, as blocking the single tube during use would restrict gas flow and stop or reduce the effectiveness of treatment.

[0136] The two tubes 3350 are fluidly connected at their lower ends to the cushion assembly 3150. In certain forms of the present technology, the connection between the tubes 3350 and the cushion assembly 3150 is achieved by connecting two rigid components such that the patient can easily connect the two rigid components in a reliable manner. Tactile feedback such as a "confirmable click" or similar sound can be used to facilitate use by the patient and also let the patient know when the tubes are properly connected to the cushion assembly 3150. In one form, the tubes 3350 are formed from silicone and the lower ends of the silicone tubes 3350 are overmolded into a rigid connector formed, for example, from polypropylene. The rigid connector can include a male mating feature configured to connect to a female mating feature on the cushion assembly 3150, although the male / female features may be arranged in other manners.

[0137] In another embodiment, a compression seal is used to connect the tube 3350 to the cushion assembly 3150. For example, if a resilient, flexible (e.g., silicone) tube 3350 is used without a rigid connector, the tube 3350 may need to be compressed slightly to reduce its diameter so that it can be pushed into the port in the plenum chamber 3200, and the inherent resilience of the silicone will push the tube 3350 outward, hermetically sealing the tube 3350 into the port. If the engagement between the tube 3350 and the port is a rigid-to-rigid type engagement, a pressure activated seal such as a peripheral sealing flange may be used. When pressurized gas is supplied through the tube 3350, the sealing flange is urged against the joint between the tube and the inner circumferential surface of the port in the plenum chamber 3200, promoting a seal therebetween. If the port is flexible and a rigid connector is provided to the tube 3350, a pressure activated seal as described above may also be used to ensure that the connection is gas-tight.

[0138] In some forms of the present technology, a similar connection mechanism may be used to fluidly connect to the tubing 3350 by a T-shaped upper member that defines or is connectable to the connection port 3600. In one embodiment, the swivel elbow connected at the connection port 3600 is rotatable such that this rotation actuates a port size adjustment mechanism that increases or decreases the size of the port into which the tubing 3350 is inserted, improving the fit of the tubing through increased or decreased compression force and reducing unintended leakage.

[0139] 8.3.3.2 Headgear Straps In certain forms of the present technology, the positioning and stabilizing structure 3300 includes at least one headgear strap which, in addition to the tube 3350, functions to position and stabilize the seal-forming structure 3100 relative to the entrance to the patient's airways.

[0140] 8.3.3.2.1 Headgear Strap Position 3A, the positioning and stabilizing structure 3300 includes rear headgear straps 3310. The rear straps 3310 are connected between two tubes 3350 that are positioned on each side of the patient's head and pass behind the patient's head (e.g., over or cover the back of the occipital bone of the patient's head in use). The rear straps 3310 connect to each tube above the patient's ears. In other embodiments, such as in the case of an oronasal mask, the positioning and stabilizing structure 3300 further includes one or more lower headgear straps. These lower headgear straps connect between the tubes and pass below the patient's ears and behind the patient's head.

[0141] In one form of the present technology, the positioning and stabilizing structure 3300 includes a chin strap 3320. The chin strap 3320 extends under the patient's chin in use, for example as shown in FIGS. 10A and 10B. The chin strap 3320 may connect to a headgear tube 3350, or in another embodiment, may connect to the cushion assembly 3150 or a frame assembly operatively connected to the cushion assembly.

[0142] Certain forms of the present technology may include multiple headgear straps for increased stability as described above (eg, rear straps, side headgear straps and chin straps).

[0143] In certain forms of the present technology, the positioning and stabilizing structure 3300 includes a mechanism for connecting headgear straps to the seal-forming structure 3100. The headgear straps may be directly or indirectly connected to the seal-forming structure 3100. In the case of the patient interface 3000 shown in FIG. 3A , tabs 3345 configured to connect to, for example, the rear straps 3310, project outwardly in a generally rearward direction from each headgear tube 3350. These tabs 3345 have holes therein for receiving the ends of the rear straps 3310.

[0144] In some forms of the present technology, the rear straps 3310 are adjustable. For example, in the patient interface shown in FIG. 3C , the rear straps 3310 are threaded through holes in each tab 3345 during use. The length of the rear straps 3310 between the tabs 3345 can be adjusted by pulling more or fewer rear straps 3310 through one or both of the tabs 3345. The rear straps 3310 can be secured to themselves by passing them through holes in the tabs 3345, for example, using a hook and loop fastener. Thus, the rear straps 3310 can be adjusted to fit different head sizes. In some forms of the present technology, the angle of the rear straps 3310 relative to the headgear tube 3350 or the patient's head can be adjusted to fit around the patient's head in different positions. Such adjustability helps the headgear 3300 accommodate different head shapes and sizes.

[0145] In some forms of the present technology, the rear straps 3345 apply a force to the headgear tube 3350 to pull the headgear tube 3350 at least partially in a rearward (e.g., backward) direction at the location of the tabs 3345. The rear straps 3310 may also apply a force to the headgear tube 3350 to pull the headgear tube 3350 at least partially in an inward (e.g., backward) direction. The magnitude of this force can be adjusted by changing the length of the rear straps 3310 between the tabs 3345.

[0146] 3C , the direction of force applied from the rear straps 3310 to the headgear tube 3350 may be changed. This direction may be changed by adjusting the angle of the rear straps 3310 relative to the headgear tube 3350 or the patient's head. In some forms of the present technology, the location at which force is applied from the rear straps 3310 to the headgear tube 3350 can be changed by adjusting the location at which the rear straps 3310 are secured to the headgear tube 3350.

[0147] Being able to adjust the magnitude and direction of force applied from the rear straps 3310 to the headgear tubes 3350 can be advantageous because it allows the headgear 3300 to accommodate a range of head sizes and shapes. The rear straps 3310 can balance the force in the headgear tubes 3350, which can help the headgear maintain its shape and obtain an effective seal against the patient's face while remaining comfortable.

[0148] In some forms of the present technology, when worn by a patient, a point on the headgear tube 3350 near the tab 3345 receives a generally upward (e.g., upward) force from the top of the headgear tube 3350 due to a biasing mechanism (described in further detail below) that functions to keep the headgear secured to the patient's head. Additionally, a point on the headgear tube 3350 near the tab 3345 may receive a generally forward (e.g., forward) and downward (e.g., downward) force resulting from the biasing mechanism that functions to urge the seal-forming structure 3150 upward and into the patient's nose. The direction and magnitude of the force required for a secure fit and effective seal may vary from patient to patient based on, for example, the location of the positioning and stabilizing structure 3300 on the head, which may vary due to differences in head shape and size. In some forms of the present technology, the rear strap 3310 is adjustable, allowing for a balance of forces to be achieved for a range of head shapes and sizes to hold the headgear 3300 in a comfortable position while maintaining an effective fit.

[0149] For example, to balance a greater force in the anterior (e.g., forward) direction on the headgear tube 3350 near the tab 3345, the rear straps 3310 can be adjusted by pulling more of them through the slots in the tab 3345, which can shorten the length of the rear straps 3310 and, if the rear straps 3310 are elastic, apply a greater force in the posterior (e.g., rear) direction to the headgear tube 3350. Similarly, the angle of the rear straps 3310 can be adjusted as needed to balance both the vertical and horizontal components of force acting on the headgear tube 3350 near the tab 3345 for a range of head shapes and sizes.

[0150] 8.3.3.2.2 Headgear strap configuration In one example, the positioning and stabilizing structure 3300 includes at least one strap 3310 having a rectangular cross section. In one example, the positioning and stabilizing structure 3300 includes at least one flat strap. In another example, the positioning and stabilizing structure 3300 includes at least one strap 3310. The profile of these straps 3310 includes one or more curved edges to improve comfort and reduce the risk of patient marks or irritation from the headgear straps.

[0151] In one form of the present technology, the positioning and stabilizing structure 3300 includes a strap 3310 constructed from a laminate of a fabric patient-contacting layer, a foam material inner layer, and a fabric outer layer. In one form, the foam material is porous to allow moisture (e.g., sweat) to pass through the strap 3310. In one form, the fabric outer layer includes a loop material that engages with a hook material portion. The hook material portion may be located on a distal portion of the strap 3310.

[0152] In certain forms of the present technology, the positioning and stabilizing structure 3300 includes a stretchable (e.g., stretchable with elasticity) strap 3310. For example, the strap 3310 can be configured to be tensioned during use and direct a force that seals the seal-forming structure 3100 against a portion of the patient's face. In one example, the strap can be configured as a tie. In other forms of the present technology, the positioning and stabilizing structure 3300 includes a strap 3310 that is adjustable to change the length of the strap. For example, a strap adjustment mechanism (e.g., a hook and loop fastener) can connect the strap 3310 to the tube 3350. The adjustable strap 3310 can add additional adjustability to other adjustment features of the patient interface 3000, improving patient comfort and fit. In some forms of the present technology, the level of adjustability provided by other portions of the positioning and stabilizing structure means that the patient interface 3000 is fully adjustable without the strap 3310.

[0153] In certain forms of the present technology, the positioning and stabilizing structure 3300 includes bendable, e.g., non-rigid, straps 3310. An advantage of this embodiment is that the straps 3310 are more comfortable when the patient lies down to sleep.

[0154] In certain forms of the present technology, the positioning and stabilizing structure 3300 includes a strap 3310 that includes two or more strap bands separated by a split. Depending on the patient interface design, the split strap 3310 may allow the patient interface 3000 to be anchored on the patient's head in a particularly stable manner.

[0155] In certain forms of the present technology, the positioning and stabilization structure 3300 provides a holding force configured to correspond to a head of a particular size and / or a face of a particular shape. For example, one form of the positioning and stabilization structure 3300 provides a holding force suitable for a large-sized head rather than a small-sized head. In another example, one form of the positioning and stabilization structure 3300 provides a holding force suitable for a small-sized head rather than a large-sized head.

[0156] 8.3.3.3 Headgear Tubing Adjustment Mechanism In certain forms of the present technology, the positioning and stabilization structure 3300 includes an adjustment mechanism 3360. The adjustment mechanism 3360 is configured to enable dimensional adjustment of the positioning and stabilization structure 3300. In at least one embodiment, the adjustment mechanism 3360 can enable adjustment of the length of the positioning and stabilization structure 3300, particularly between the connection port 3600 and the seal-forming structure 3100 (e.g., adjustment of the length of the tie (e.g., headgear tubing 3350)). Additionally or alternatively, the adjustment mechanism 3360 is configured to enable adjustable bending of the positioning and stabilization structure 3300 (e.g., bending of the headgear tubing 3350). The adjustment mechanism 3360 enables adjustment of the patient interface 3000 to improve the fit of the patient interface 3000 to the patient's head, thereby enabling the patient interface 3000 to fit heads of different sizes. A patient interface that fits the patient can be worn comfortably, resulting in increased stability, reduced likelihood of seal breakage, and maintenance of a sealed structure at the entrance of the patient's airway with a comfortable level of headgear tension. These factors improve patient compliance with treatment and treatment outcomes. It is understood that the adjustment mechanism can include multiple mechanisms for adjustment. For example, the combinations of adjustment mechanisms described below can be provided to the headgear in some forms of the present technology.

[0157] For example, the adjustment mechanism 3360 may allow for adjustment of the size and / or shape of the patient interface 3000. In one form of the present technology, the length of the tube 3350 between the connection port 3600 and the seal-forming structure 3100 may be adjusted.

[0158] In some forms of the present technology, the adjustment mechanism 3360 may allow the size of the patient interface 3000 to be adjusted by up to 100 mm so that the patient interface 3000 fits a wide range of patients. For example, the adjustment mechanism 3360 may allow the total length of the tubes 3350 to be adjusted by up to 100 mm. In one form of the present technology, the total length of the tubes 3350 may be adjusted by up to 80 mm. For example, the length of the tubes 3350 that will be placed on each side of the patient's face in use may be adjusted by up to 40 mm.

[0159] The patient interface 3000 may be configured and constructed such that the force exerted by the positioning and stabilizing structure 3300 on the patient's face to maintain a sealing relationship between the cushion assembly 3150 and the patient's face against the force exerted by the positive pressure gas in the plenum chamber 3200 is approximately constant or within predetermined limits over a range of sizes that the patient interface 3000 can accommodate, as will be described in more detail below.

[0160] Different forms of the adjustment mechanism 3360 are described below. In some forms, the adjustment mechanism 3360 is included as part of the headgear tubing 3350, while in other forms the adjustment mechanism 3360 is remote from the headgear tubing 3350. Certain forms of the present technology may include multiple adjustment mechanisms 3360 as described below.

[0161] In some forms of the present technology, the adjustment mechanism 3360 is configured to be manually adjusted (i.e., adjusted by the patient or another person) so that the patient interface 3000 can be fitted to the patient for comfort and therapeutic effectiveness. In other forms, the adjustment mechanism 3360 is configured to automatically adjust to fit the patient. An automatic adjustment mechanism can be advantageous because it reduces the likelihood of an incorrect or uncomfortable fit of the patient interface 3000 to the patient. However, some patients may prefer to be able to alter the fit of the patient interface themselves.

[0162] In some forms of the present technology, the patient interface 3000 is configured so that different forms of the seal-forming structure 3100 can be interchangeably connected to the positioning and stabilizing structure 3300. Different forms of the seal-forming structure 3100 can include seal-forming structures of different sizes and weights. For example, an oral-nasal cushion can be heavier than a nasal cushion. In such forms of the present technology, the use of a manual adjustment mechanism can provide the advantage of allowing the mechanism to be initially set to suit the type of seal-forming structure being used. For example, the manual adjustment mechanism can be set to provide a tighter fit when a heavier seal-forming structure is used to reduce the tendency of the heavier seal-forming structure to pull the positioning and stabilizing structure 3100 downward. Similar considerations can apply to seal-forming structures that are exposed to movement of the patient's mouth (e.g., wide-mouthed movements).

[0163] 8.3.3.3.1 Collapsible / bellows headgear tubes In certain forms of the present technology, the adjustment mechanism 3360 comprises a tube 3350 having one or more fold regions, pleats, corrugations, or bellows. That is, the fold region pleats, corrugations, or bellows comprises the adjustment mechanism 3360. When each fold region is initially in a first folded configuration, the length of each tube 3350 is different from the length when the fold region is in a second, unfolded configuration.

[0164] The patient interface 3000 shown in FIG. 3A includes a tube 3350 that includes a corrugated tube section 3362. The corrugated tube section 3362 spans the length of the non-corrugated tube 3350. The corrugations or bellows include a plurality of pleats or bellows. These pleats or bellows can be individually folded or unfolded or can cooperate to shorten or lengthen the corrugation tube 3362 and thus each tube 3350. The pleats in the corrugation tube 3362 can be expanded (stretched) or contracted by varying the degree on different sides of the tube 3350. For example, the corrugations on the side of the tube 3350 closest to the patient's head can be contracted to a greater degree than the corrugations furthest from the patient's head to increase the curvature of the tube 3350. As a result, the shape and length of the tube 3350 can be varied, which also helps to adjust the patient interface to fit a patient's specific head size and shape.

[0165] In certain forms of the present technology, the bellows tube 3362 allows the length of the tube 3350 of the patient interface 3000 to be continuously adjusted through a range of different lengths. In some embodiments, the length of each bellows tube may be continuously adjustable. An adjustment mechanism such as a bellows section that provides continuous adjustment may comfortably fit a wide range of head sizes. In contrast, an adjustment mechanism that provides adjustment between discrete lengths may provide a less comfortable fit for patients who require a length between two of the discrete length options for an optimal fit.

[0166] In some forms of the present technology, a tube 3350 includes multiple corrugated tube sections 3362 in place, each of which is separated by a length of uncorrugated tube 3350.

[0167] In some forms of the present technology, the corrugated tube section 3350 is provided within a relatively straight section of the tube 3350. This avoids the tendency of the corrugated section 3350 to straighten when pressurized gas passes through the tube 3350. If the corrugated section 3350 were to straighten, the position of the patient interface on the patient's head could change, which could adversely affect seal stability and / or flow impedance.

[0168] 3B, the patient interface 3000 includes a tube 3350 that includes a corrugated tube 3362. The corrugated tube 3362 is longer than the corrugated tube 3362 shown in FIG. 3A. In the form of the technology shown in FIG. 3B, the corrugated tube 3362 extends for the majority of the length of each tube 3350, between the point where the headgear strap 3310 connects to the tube 3350 and the point where the upper end of the tube 3350 connects to the connection port 3600. For example, the corrugated tube 3362 may have a lower end directly above the point where the headgear strap 3310 connects to the tube 3350, and an upper end at the point where the tube 3350 connects to the connection port 3600. A longer corrugated tube may also increase the compliance of the tube 3350. Alternatively, compliance may be increased by increasing the number of corrugations in the corrugated tube 3362. Increased compliance can be advantageous as it allows the patient interface 3000 to fit multiple patients with a wide range of head sizes while still providing a desired level of retention on the patient's face to ensure a good seal across this range of head sizes.

[0169] In the form of the present technology shown in Figures 3C, 3D, and 3E, the patient interface 3000 is similar to the patient interface 3000 shown in Figure 3B. One difference is the configuration of the corrugated tubes 3362. In the form of the present technology shown in Figures 3C, 3D, and 3E, the width and diameter of the corrugated tubes 3362 vary along the length of each corrugated tube 3362. More specifically, the corrugated tubes 3362 are tapered such that the tube width and diameter at one end of each corrugated tube 3362 is smaller than the tube width and diameter at the other end of each corrugated tube 3362. In even more detail, the width and diameter of the upper end of each corrugated tube 3362 (where the corrugated tube 3362 connects to the connection port 3600) is greater than the width and diameter of the lower end of each corrugated tube 3362 (where the corrugated tube 3362 connects to the portion of the tube 3350 without bellows), and the width and diameter of the corrugated tube 3362 gradually increase between the upper and lower ends and are generally linear. The tapered shape of the corrugated tube 3362 is also shown in Figure 3F. Figure 3F is a top view of the patient interface 3000 of Figures 3C, 3D, 3E, and 3G. Figure 3G shows the patient interface 3000 of Figure 3F in cross section along line 3G-3G. The tapered shape of the bellows tube portion 3362 fluidly connects the connection port 3600 to the bellows-free lower length of the tube 3350 in a manner that reduces discontinuities in the cross-sectional profile of the air path, thereby providing a smooth transition that reduces impedance buildup and promotes fluid flow along the tube 3350.

[0170] One advantage of the bellows tube 3362 for the adjustment mechanism 3360 is that it can curve or bend and extend more easily in the longitudinal direction compared to other adjustment mechanisms. Figure 3J shows the headgear 3300 worn in three different positions on a patient's head, designated by the suffixes "a," "b," and "c." As shown in Figure 3J, bellows tubes 3362a, 3362b, and 3362c are curved to different levels, with bellows tube 3362a curving forward on the patient's head, bellows tube 3362b curving less in the posterior / anterior direction, and bellows tube 3362c having substantially no curvature on the patient's head.

[0171] In some forms of the present technology, the corrugated tube 3362 may stretch different amounts on the anterior and posterior (e.g., anterior and posterior) sides of the headgear tube 3350. That is, the walls forming the corrugated tube 3362 may be relatively more contracted (e.g., folded more) on one side of the tube and relatively more stretched (e.g., folded less) on the other side of the tube, thereby facilitating a bend or curved shape in the tube. This effect is shown in FIG. 3L. As shown, the walls of the corrugated tube 3362 stretch less (e.g., buckle more) anteriorly than posteriorly in the case of corrugated tube 3362a (i.e., when the headgear is worn on the patient's head anterior to the coronal plane). The ability of the bellows tube 3362 to curve in the forward direction assists in allowing the headgear 3300 to be donned in a forward position without having to rotate the cushion assembly 3150 forward to remove it from sealing contact with the patient's face (as would be the case if the headgear tube were rigid). The ability of the headgear tube 3350 to curve in either the forward or rearward direction assists in disconnecting the connection port 3600 from the cushion assembly 3150. The difference in extension of the bellows tube 3362c between the front and rear sides of the bellows tube 3362c (i.e., when the headgear 3300 is donned in a rearward position on the patient's head) is less than the difference in extension of the bellows tube 3362a between the front and rear sides of the bellows tube 3362a (i.e., when the headgear 3300 is donned in a forward position on the patient's head). Such bellows reduces the degree to which the headgear tube 3350 becomes straight (or curved) when donned in a rearward position.

[0172] In one form, the bellows section 3362 on each side of the patient interface 3000 is approximately 40 mm longer in the fully expanded configuration than in the fully retracted configuration.

[0173] In other forms of the present technology, the bellows tube portion 3362 can be disposed at different portions of the length of the tube 3350. As shown in FIGS. 3A and 3B, the bellows tube portion 3362 is disposed at a position along the length of the tube 3350 such that the bellows tube portion 3362 contacts the upper part and / or the upper side of the patient's head (i.e., the region of the patient's head above the nasion of the patient's head). One advantage of the patient interface 3000 is that the bellows tube portion 3362 does not contact the patient's cheek region. As a result, discomfort that may occur when the bellows tube portion contacts the patient's cheek region during use is avoided.

[0174] The bellows tube portion 3362 is prone to buckling, especially when it is particularly large and extended. Therefore, as a result of the bellows tube portion 3362 causing the tube 3350 to become clogged, there is a risk that the delivery of breathable gas to the patient is restricted or avoided. In some forms of the present technology, the patient interface 3000 includes one or more structures configured to avoid or at least characterize the buckling of the bellows tube portion 3362. In one embodiment, the patient interface 3000 includes one or more high-rigidity rings or semi-rigid rings. These rings are provided to the bellows tube portion 3362 and are circumferentially arranged around the tube 3350. For example, these rings may be disposed inside the bellows tube portion 3362, or may be molded (e.g., co-molded or over-molded) together with the bellows tube portion 3362. In another embodiment, a helical element for buckling suppression is provided along the bellows tube portion 3362. In such an embodiment, the material portion between the pitches of each helical winding known as a tape can impart elasticity to the tube. The tape may be formed of an elastic material, or may be structured such that an appropriate level of elasticity sufficient to impart a tension for contraction to the tube can be obtained. In other embodiments, the bellows tube sub-portions formed together with the bellows tube portion 3362 are thicker or are composed of a more highly composite material than other bellows tube sub-portions for buckling suppression.

[0175] In another form of the present technology, a patient interface includes an adjustment mechanism 3360 that includes a tube 3350. The tube 3350 has one or more circumferential folds for folding adjacent portions of the tube 3350 longitudinally. When the circumferential folds are in the folded configuration, lengths of the tube cover adjacent lengths of the tube. The stiffness of the material from which the tube is formed can be configured such that the tube tends to remain in the folded configuration unless pulled apart by a substantial force (e.g., greater than the force exerted on the tube during typical use of the patient interface). Alternatively, the patient interface can include a means (e.g., a clip) to maintain the tube in the folded configuration. In another embodiment, magnets are embedded in the tube that align the overlapping fold sections (unless the magnets are pulled apart) when the tube is folded to maintain the tube in the folded configuration.

[0176] The patient interface 3000 shown in Figure 5 includes an adjustment mechanism 3360 that includes a folding portion 3364. The folding portion 3364 includes a first tube wall section 3366. The first tube wall section 3366 can be rotated onto the adjacent tube section 3368 to fold at different levels. Figures 5A and 5B are cross-sectional views of the folding portion 3364 of the patient interface 3000 shown in Figure 5. In Figure 5A, the rotated folding portion 3366 is folded onto the adjacent tube section 3368 at a higher level than it is folded onto in Figure 5B, such that the length of the tube 3350 when the folding portion 3364 is in the configuration shown in Figure 5B is longer than the length of the tube 3350 when the folding portion 3364 is in the configuration shown in Figure 5A. 5A and 5B, at the location of the fold 3364, three layers of the tube 3350 overlap each other, but the length of the overlapped tube section differs between the configurations of Figures 5A and 5B. The rotational fold 3366 may include a localized section of the tube wall that is thinner than other portions of the tube 3350.

[0177] 6 shows another form of the folding adjustment mechanism 3360 of the positioning and stabilizing structure 3300 of the patient interface 3000. In this embodiment of the present technology, the tube 3350 extends from the connection port 3600 to a tube end 3352. The tube end 3352 is configured to connect to the cushion assembly 3150 of the patient interface 3000. The tube 3350 has a generally wavy shape along its length and includes at least one curved section (e.g., curved section 3353A, 3353B). The tube 3350 is formed from a material that is sufficiently flexible so that the curved section can increase or decrease curvature to allow each tube to fit smaller or larger heads, respectively. For example, the tubes may be formed from metasilicone that has a hardness of 40 durometers on the Shore scale.

[0178] 6, the tube 3350 on one side of the patient's head extends at its upper end in a generally anterior-posterior direction away from the connection port 3600 and in a generally downward direction on the side of the patient's head near the point where the headgear strap 3310 attaches to the tube 3350, with the upper curved section 3353A positioned edge generally covering the upper side of the patient's head and the outer side of the curved section on the anterior side and the inner side of the curved section on the posterior side. Below the point where the headgear strap 3310 attaches to the tube 3350, the tube 3350 extends in a generally downward direction and curves slightly forward in the anterior direction. The lower curved section 3353B is positioned generally above the patient's cheek area in use. The lower end of the tube 3350 extends generally horizontally in the anterior direction over the patient's cheek to a tube end 3352 that connects to the cushion assembly 3150. The lower end of the tube 3350 may be oriented slightly downward (i.e., extend slightly downward when worn by some patients). The lower curved portion 3353B, which is generally positioned over the patient's cheek area, has an outer curved portion at the posterior side and an inner curved portion at the anterior side.

[0179] 6 is constructed and arranged such that in use the tube 3350 is positioned generally away from the patient's eyes, such that the tube 3350 does not, or at least minimally, enter the patient's field of view. This may be achieved by constructing the lower portion of the tube 3350 such that the apex or point of maximum curvature of the lower curved portion 3353B is positioned over the posterior region of the patient's cheek area in use.

[0180] 6, the tube 3350 located on the left side of the patient's face is constructed symmetrically relative to the tube 3350 on the right side of the patient's face. In other configurations, the tube 3350 may have different configurations on each side of the patient's face.

[0181] 8.3.3.3.2 Telescopic headgear tubes In a particular form of the present technology, the adjustment mechanism 3360 includes a tube 3350 having a first tube portion 3370. The first tube portion 3370 is telescopically movable relative to a second tube portion 3372.

[0182] The patient interface 3000 shown in FIG. 7A includes an adjustment mechanism 3360 including a first tube portion 3370 and a second tube portion 3372. The first tube portion 3370 and the second tube portion 3372 slide telescopically relative to one another. In the embodiment of FIG. 7A , the first tube portion 3370 connects to the connection port 3600 and is therefore positioned higher on the patient's head than the first tube portion when the patient interface is worn. The second tube portion 3372 has a smaller diameter than (i.e., fits inside) the first tube portion 3370 and is fixedly connected to a portion of the tube 3350 that is positioned lower on the patient's head when the patient interface is worn. The first tube portion 3370 may be described as covering the second tube portion 3372 through the telescopic movement between the first tube portion 3370 and the second tube portion 3372.

[0183] In certain forms of the present technology, the patient interface includes a tube fixation mechanism. The tube fixation mechanism secures the first tube section 3370 and the second tube section 3372 to one another in a plurality of discrete positions. For example, in the form of the present technology shown in FIG. 7A , the second tube section 3372 includes a plurality of raised ribs 3374 on its outer surface, and the first tube section 3370 includes one or more protrusions or detents (not shown). These protrusions or detents interact with the ribs 3374 to hold the first tube section 3370 and the second tube section 3372 in a plurality of relative longitudinal positions, allowing adjustment of the length of the tube 3350. In other forms of the present technology, the tube sections may be secured in a plurality of discrete positions using other interlocking mechanisms (e.g., one or more grooves or holes interacting with one or more protrusions or detents). It will be understood that these grooves may be provided on the surface of the first tube portion or the second tube portion, with protrusions provided on the surface of the other of the first tube portion or the second tube portion in a position that will interlock with the grooves in use.

[0184] 7B includes a first tube 3370 and a second tube 3372. The patient interface 3000 includes an adjustment mechanism 3360. The first tube 3370 and the second tube 3372 slide telescopically relative to one another. The first tube 3370 can slide over the outer surface of the second tube 3372. The second tube 3372 is positioned below and above the patient's head relative to the first tube 3370 when the patient interface 3000 is worn (i.e., the second tube 3372 is located downstream of the first tube 3370). The patient interface 3000 includes two similar such adjustment mechanisms 3360, one located on each side of the patient's head in use.

[0185] The patient interface 3000 includes an upper tubular member 3351. The upper tubular member 3351 is placed on top of the patient's head in use. A first tube section 3370 on each side of the patient's head is integrally formed as part of the upper tubular member 3351. A connection port 3600 is provided in the upper tubular member 3351, for example the upper tubular member 3351 has an opening in the upper side at a central portion thereof.

[0186] The first tube portion 3370 on each side of the patient's head may include a first or upper tab 3371, and the second tube portion 3372 may include a second or lower tab 3373. The second tab 3373 may be pressed toward the first tab 3371. For example, a user may place their thumb on the second tab 3373 and their index finger on the first tab 3371 and pinch the two tabs together such that the second tab 3373 moves toward the first tab 3371. Moving the second tab 3373 toward the first tab 3371 causes the first tube portion 3370 and the second tube portion 3372 to slide telescopically, shortening the headgear tube 3350. When the second tab 3373 is moved away from the first tab 3371, the first tube portion 3370 and the second tube portion 3372 slide telescopically, thereby lengthening the headgear tube 3350.

[0187] When the second tab 3373 is slid onto the peripheral edge of the first tube 3370, it acts as a stop to prevent further shortening of the tube 3350 when it contacts the peripheral edge.

[0188] 7B is formed integrally with the length of tube 3350 which is positioned to contact the sides of the patient's head and over the patient's cheek area in use. To enable the patient interface 3000 to be comfortable to wear and to conform to a range of patient head shapes, the lower portion of the tube 3350 (of which the second tube portion 3370 is an integral part) may be formed from a semi-rigid material such as an elastomeric material (e.g., silicone). In contrast, the upper tube member 3351 (and therefore the first tube portion 3370) may be formed from a relatively rigid material.

[0189] One possible consequence of telescopically moving a patient interface in which the tubes are made of a relatively flexible material into tubes made of a relatively rigid material is that the tube made of the relatively flexible material may buckle when the inner tube is pressed into the outer tube. This may affect the adjustability of the length of the tube 3350. The patient interface 3000 shown in FIG. 7B includes a stiffening member 3379 to address this issue. The stiffening member 3379 functions to increase the stiffness of the portion of the second tube 3372 that moves in and out of the first tube 3370 during use. In the illustrated embodiment, the stiffening member 3379 is a length of relatively rigid material attached to the upper side of each second tube 3372. The stiffening member 3379 may be attached to the outside of the second tube 3372 or may be molded (e.g., co-molded or over-molded) as part of the second tube 3372. In certain forms of the present technology, each stiffening member 3379 may be integrally formed with a tab 3373 on the upper side of the tab 3373 on each second tube portion 3372 .

[0190] The patient interface of FIG. 7B includes a padded member 3330 on the patient-contacting side of the upper tubular member 3351 to improve comfort when the patient interface 3000 is worn. One or more padded members 3330 may be provided on any portion of the positioning and stabilizing structure 3300 of any of the patient interface 3000 configurations described herein, unless otherwise specified. For example, the padded member 3330 may be provided as part of the tube 3350 to make the patient interface more comfortable to wear. The padded member 3330 may be permanently attached to a portion of the tube 3350, for example, by molding (e.g., co-molding or overmolding) or adhesive. Alternatively, the padded member 3330 may be removably attached to the tube 3350, for example, using hook-and-loop fasteners or fasteners. The padded member 3330 comes into contact with the patient's head during use and may become soiled. It may be advantageous to be able to remove the padded member 3330 for cleaning and / or replacement.

[0191] Another form of the present technology is shown in Figure 7C. In this form, the patient interface 3000 includes a second tube 3372. The second tube 3372 slides telescopically onto the exterior of the first tube 3370. That is, the tube that telescopically fits inside the other tube will be positioned higher on the patient's head than the other tube in use.

[0192] In the embodiment of FIG. 7C , the first tube portion 3370 is relatively rigid. The second tube portion 3372 includes a relatively rigid ring member 3384 at its upper end. The ring member 3384 surrounds an opening in the upper end of the second tube portion 3372. The second tab 3373 may be provided on the ring member 3384 (e.g., formed integrally with the ring member 3384). Because both the first tube portion 3370 and the second tube portion 3372 are formed from a relatively rigid material, they can move telescopically relative to one another without buckling. Thus, the patient interface 3000 shown in FIG. 7C may avoid the need for a stiffening member as described in connection with FIG. 7B while still allowing the same length extension of the tube 3350.

[0193] Another form of telescopic adjustment of the tube 3350 is shown in FIG. 8. In this embodiment, the second tube section 3372 of the tube 3350 slides telescopically relative to the first tube section 3370 with a ratchet mechanism 3376. The ratchet mechanism prevents or inhibits the telescopically movable first and second tube sections from moving relative to one another in one or both directions unless the ratchet mechanism is released, for example, by pressing a button 3378. Each button 3378 is operatively connected to a locking member (not shown). The locking member (not shown) interfaces with a groove or protrusion (e.g., rib 3374) on the second tube section 3372 unless the button 3378 is pressed.

[0194] Another form of ratchet mechanism 3376 is shown in the form of the present technology shown in FIG. 7C . In this form, the ratchet mechanism 3376 includes a tongue 3397 on the head-contacting side of the second tube portion 3372. The tongue 3397 is connected to the second tube portion 3372 at its lower end and extends generally along the length of the second tube portion 3372. The tongue 3397 is free at its upper end and has a protrusion on its upper side. The first tube portion 3370 includes a plurality of grooves 3398 on its head-contacting side. The protrusions on the ends of the tongue 3397 are configured to selectively mate with each of the grooves 3398 to hold the first tube portion 3370 and the second tube portion 3372 in relative positions. The tube 3350 may have a generally D-shaped cross section, with the flat portion of the "D" contacting the patient. The ratchet mechanism 3376 may be advantageously located on the head contacting side of the patient interface 3000 (e.g., as in FIG. 7C) because the tongue and groove ratchet mechanism 3376 may be more effective when provided on a relatively flat area of the tube 3350, as it provides a larger contact area than if there were a large mating curved surface within the ratchet mechanism.

[0195] 360。 In another form of the present technology, the button 3378 includes tabs located on the side of the tube 3350. These tabs can be squeezed inward to release the interlocking mechanism, allowing the telescopic tube sections to move relative to one another. These tabs can include a gap or window in the first tube section 3370 that surrounds the second tube section 3372, allowing the patient or clinician to squeeze a portion of the second tube section 3372 to release the interlocking. Alternatively, the gap can be covered by one or more overmolded buttons. Pressing these buttons can tighten the second tube section 3372 to release the interlocking. Covering the gap with an overmolded button or eliminating the gap in the adjustment mechanism 3360 reduces the chance of the patient's hair getting tangled in the adjustment mechanism 3360, which can be uncomfortable. In one exemplary embodiment, the adjustment mechanism 3360 is configured such that when the sides of the ring member 3384 at the top end of the second tube portion 3372 are pressed inward, an interlocking feature between the second tube portion 3372 and the first tube portion 3370 is released, allowing telescopic movement between the tube portions. For example, the ring member 3384 may include a silicone overmolded hard plastic pinch button and one or more protrusions on its inner top surface to interlock with grooves on the top surface of the first tube portion 3370, which are forced out of interlocking engagement when the ring member 3384 is squeezed inward at the sides.

[0196] The patient interface of Figure 8 includes a padded member 3330 on the patient contacting side of the positioning and stabilising structure 3300, which increases comfort when wearing the patient interface 3000.

[0197] Another form of telescopic adjustment of the tube 3350 is shown in FIG. 9. In this embodiment, the tube 3350 includes a plurality of nested concentric tube sections 3375a, 3375b, and 3375c that slide relative to one another. Each nested concentric tube section 3375 can be fully exposed or fully covered by telescopically extending or retracting adjacent nested concentric tube sections 3375 relative to each other. The nested concentric tube sections interlock with one another (e.g., via a snap-fit mechanism) to hold their positions in the fully extended or retracted positions. In some embodiments, the nested concentric tube sections 3375 can be held in an intermediate position (i.e., not fully extended or retracted).

[0198] In the embodiment shown in FIG. 9, each nested concentric tubular section is marked with a visual indicator 3377 indicating the length of the tubing 3350. When the tubing section is exposed, for example, "S" for small 3377a, "M" for medium 3377b, and "L" for large 3377c are indicated. Other forms of indicators may be used (e.g., numerical or colored indicators). Physical indicators, such as embossments, may also be used, which may be advantageous when the patient is sleeping in a dimly lit room. The nested concentric tubular sections 3375a-3375c may be configured to extend or retract in a predetermined sequence.

[0199] Other forms of the present technology include tubes 3350 formed from multiple telescopic tube sections interconnected in other ways. For example, each tube 3350 can include a central inner tube section with two outer tube sections on either side, which slides telescopically in and out of each of these two outer tube sections in use. Alternatively, the central tube can be external to the two outer tube sections.

[0200] In other forms of telescopically adjustable headgear tubes, other forms of size indicators may be provided. In certain forms, the first tube section 3370 of the tube 3350, which surrounds the second tube section 3372 during telescopic movement between the two tube sections, may include a window or gap through which a visual indicator 3377 on the second tube section 3372 may be viewed to indicate the size of the tube 3350 so provided.

[0201] Another telescopic adjustment mechanism 3360 for the headgear tube 3350 is shown in FIG. 10A . In this embodiment, the length of the headgear tube 3350 can be adjusted by an adjustment mechanism 3360 including a tooth or pinion 3383. Rotation of the tooth or pinion 3383 causes ribbed or rack-shaped portions of adjacent first and second tube sections 3370, 3372 of the tube 3350 to move telescopically, thereby changing the length of the tube 3350. The connection of the first tube section 3370 to the cushion assembly 3150 can be integral, permanent, or removable. In the embodiment shown in FIG. 10A , the adjustment mechanism 3360 is located at the lower end of the headgear tube 3350. For example, the adjustment mechanism 3360 can be located adjacent to the cushion assembly 3150. In the embodiment shown in FIG. 10A , rotation of the tooth or pinion 3383 causes the lower end of the tube 3350 to move telescopically relative to the cushion assembly 3150.

[0202] In another form of the present technology, the adjustment mechanism 3360 is placed into the connection port 3600 and the swivel elbow is mounted to a tooth or pinion so that as the elbow rotates, the headgear tube sections move relative to each other or to the T-shaped connection port member. When the desired arrangement is achieved, a lock can be provided to prevent or limit rotation of the elbow.

[0203] It will be appreciated that when a discrete number of relative positions of the first and second tube sections are provided by the telescopic adjustment mechanism, the greater number of positions allows for a greater number of adjustment positions, facilitating an improved fit to the patient. In some embodiments, three, four, five, six or more adjustment positions are provided.

[0204] In certain forms of the present technology, the telescopic tube sections are configured to move relative to one another and to be adjusted in a continuous manner (i.e., the relative positions of the tube sections are not limited to discrete positions), allowing for greater customization of the length of the tube 3350.

[0205] An example of a tube 3350 having a continuously adjustable length is shown in Figure 10B. In Figure 10B, a tube section 3372 includes a first threaded portion 3382 on the first tube section 3370. The first threaded portion 3382 is threadedly engaged with a second threaded portion 3380 on the second tube section 3372. Rotating one of the threaded portions relative to the other adjusts the length of the tube 3350 by translating the rotational movement into relative longitudinal movement of the associated tube section. One or both of the threaded portions are connected in rotational engagement with the other portion of their respective tube section, such that rotation of the threaded portion does not rotate the remainder of the tube 3350. An enclosed or smaller diameter first threaded portion 3372 may be provided on the lower end of the tube 3350 (i.e., the portion of the tube 3350 connected to the cushion assembly 3150 (as shown in FIG. 10B) or to the upper end of the tube 3350 (i.e., the portion of the tube 3350 connected to the connection port 3600)). An abutment or thread limiting member (not shown) may be provided on one end of one of the threaded portions to prevent the threaded portion from being unscrewed and removed during use.

[0206] In one form of the present technology, a screw mechanism is provided as a fine adjustment mechanism in addition to a coarser adjustment mechanism, which may be, for example, any of the other adjustment mechanisms described herein. Generally, any of the adjustment mechanisms described herein may be used in combination with a first adjustment mechanism that allows for finer adjustment than the second adjustment mechanism.

[0207] In another embodiment of the present technology, the telescopic sliding portions of the tube 3350 are held in frictional contact via ribs on the sliding surfaces of one or both sliding portions. Alternatively, one or more O-rings may be provided between the telescopically sliding tube sections. These ribs or O-rings hold the tube sections with enough friction to hold them in the desired position during normal use of the patient interface, but allow their relative position to be adjusted upon application of sufficient longitudinal adjustment force.

[0208] In another form of the present technology, the telescopic tube sections may be secured in place using other securing mechanisms. In one example, a length of strap is attached to one of the telescopic tube sections with a section of hook and loop fastener material on the strap. This strap can be secured to a complementary section of hook and loop fastener material on the other telescopic tube section (to secure the section in a desired position), thereby allowing adjustment of the length of the tube 3350.

[0209] It will be appreciated that in the above-described embodiments of the present technology where one or more tube sections are telescopically movable relative to the other tube sections, the tube sections are telescopically engaged in a substantially sealed manner, thereby reducing the amount of leakage of breathable gas from the patient interface. The manner in which this is achieved will depend on the nature of the telescopic engagement, but one or more O-rings or other sealing members may typically be provided.

[0210] 7B , for example, an O-ring is provided on the inner surface of the lower end of the first tube portion 3370. For example, the O-ring may be provided in a slot on the inner surface of the lower end of the first tube portion 3370. The O-ring is in sealing contact with the outer surface of the upper end of the second tube portion 3372. In other forms of the present technology, the O-ring may be provided on the outer surface of the upper end of the second tube portion 3372. In one example, the O-ring may be provided on or integrally formed with the stiffening member 3379.

[0211] The configuration and structure of the sealing contact between the telescopically moving first and second tube sections may be selected to provide an appropriate level of friction to achieve a balance between the quality of the seal and the ease of adjustment of the first and second tube sections. It has been found that in some forms of the present technology (e.g., the patient interface 3000 shown in FIG. 7B ), the minimum holding force between the first and second tube sections 3370, 3372 may be approximately 10 N, and the maximum holding force may be approximately 20 N. If the holding force is less than the predetermined minimum amount, the first and second tube sections may move apart too easily, for example, when shaken by the patient or due to the patient's bending or as a result of positive pressure gas flow through the tube 3350, and the length of the tube 3350 may be accidentally adjusted during normal use of the patient interface 3000. If the holding force exceeds the predetermined maximum amount, it may become excessively difficult for the patient to move the first and second tube sections to adjust the length of the tube 3350.

[0212] In another form of the present technology, the interior or exterior surfaces of the first tube 3370 or second tube section 3372 may include one or more movable flap seals, lip seals or compressible gasket seals. In another form, leakage between the first tube section 3370 and the second tube section 3372 may be controlled to prevent interference with respiratory pressure therapy. In one form, the controlled leakage may function as an additional flush vent.

[0213] In the above forms of the present technology where one or more tube sections are telescopically movable relative to the other tube sections, the patient interface 3000 may include one or more end stops to prevent the first tube section 3370 and the second tube section 3372 from moving apart. In one form, the inner tube section includes a flange at its end and the outer tube section includes an end stop on its inner surface that abuts the flange at the tube sections' maximum extension.

[0214] Although a swivel elbow has been described, a ball and socket elbow may alternatively be used, allowing six degrees of freedom to increase decoupling of tube drag forces.

[0215] 8.3.3.3.3 Modular pipe sections 11, the adjustment mechanism 3360 takes the form of an interchangeable tube section 3385. The interchangeable tube section 3385 can be removed from the patient interface 3000 and replaced with a replacement tube section 3386 having a different length relative to the first tube section or module 3385. The interchangeable and replacement tube sections 3385 and 3386 may be described as tube modules.

[0216] 11, the replaceable tubing section 3385 comprises a T-shaped tubing member having three ports such that, in use, the replaceable tubing section 3385 fluidly connects to the tubing 3350 and the air circuit 4170, respectively. For example, the upper, central port of the replaceable tubing section 3385 is configured to connect to or include the connection port 3600. For example, the replaceable tubing section 3385 may be positioned on the patient's head in use.

[0217] The tube 3385 can be separated from the rest of the patient interface 3000 and replaced with replacement tubes 3386a and 3386b that have tubes that extend outwardly from the connection port 3600 by different amounts relative to the replaceable tube 3385. While any number of replacement tubes can be provided, in the embodiment of Figure 11, the patient interface 3000 includes "small," "medium," and "large" replaceable sections.

[0218] 12 , the patient interface 3000 includes one or more tube inserts 3387a and 3387b. These tube inserts 3387a and 3387b are configured to be selectively fluidly connected to the tube 3350 to vary the length of the tube. For example, the tube inserts 3387a and 3387b are configured to be fluidly connected between the tube 3350 and the cushion assembly 3150 to vary the effective length of the tube 3350. In another embodiment, the tube inserts may be connected to other portions of the patient interface, for example, at the upper end of the tube 3350 between the tube 3350 and the connection port 3600. Each tube insert 3387 may be marked with a size designation (e.g., "M" for "medium" and "L" for "large"). A single size patient interface can be achieved without inserting a tube insert.

[0219] 8.3.3.3.4 Cuttable tubes In another embodiment of the present technology, the tube 3350 can be cut to a desired length. To assist the patient or clinician in determining where to cut the tube 3350, these tubes may include one or more indicators indicating where to cut the tube to fit the patient interface to heads of different sizes. For example, lines or punched holes indicating where to cut may be provided around the diameter of the tube 3350. For each line or punched hole, marks of sizes such as "small", "medium" or "large" may be provided. The cutting marks on the tube 3350 may be provided on the lower end of the tube configured to connect to the cushion assembly 3150 or on the upper end of the tube configured to connect to the connection port 3600.

[0220] In one embodiment, a cutting tool configured to cut the tube 3350 is supplied for the patient interface.

[0221] As a disadvantage of cutting the tube 3350 according to the size of the patient interface, if the tube is accidentally cut too short, it may be difficult to replace the cut portion of the tube.

[0222] 8.3.3.3.5 Extendable tube In a particular form of the present technology, the adjustment mechanism includes one or more extendable portions 3355 of the headgear tube 335 formed of an extendable material. The extendable portion enables the length of the tube 3350 to be continuously adjusted according to patient heads of different sizes. It is understood that a part of the tube may be extendable by the material constituting the tube (for example, when constituted by an extendable material), its configuration (for example, the bellows tube portion 3362 shown in FIG. 3A is extendable by its configuration) or both.

[0223] 13 has a relatively stretchable section of tube 3355 connected to one or more non-stretchable or less stretchable sections of tube 3354. A securing mechanism 3356 may be provided to hold the tube 3350 in place once the desired length has been achieved. The securing mechanism 3356 may include a first securing member 3357 attached to the length of tube 3350 on one side of the stretchable portion 3355 and a second securing member 3358 attached to the length of tube 3350 on the other side of the stretchable portion 3355. The first securing member 3357 and the second securing member 3358 are configured to be connected together by any suitable mechanism (e.g., interlocking clips, magnetic connections, hook and loop fasteners). One of the securing members 3358 may include multiple locations where other securing members 3357 may be connected to the securing member 3358, allowing the tube 3350 to be secured at a desired length.

[0224] In another embodiment, no locking mechanism is provided and the constant length of the tube 3350 is automatically achieved by the elastic contraction of the stretchable portion 3355 .

[0225] The stretchable portion of the tube 3355 may include a thinner-walled portion than the less stretchable portion 3354. Alternatively or additionally, the stretchable portion of the tube 3355 may include a portion that is softer than the less stretchable portion 3354 and / or formed from a material having a lower durometer than the less stretchable portion 3354.

[0226] In one embodiment, the stretchable portion of the tube 3355 has a cross-sectional thickness that decreases along its length. For example, the cross-sectional thickness may decrease in a graduated longitudinal cross-section. Alternatively, the cross-sectional thickness of the tube portion 3355 may alternate between thicker and thinner longitudinal cross-sections. The surface transition between portions of different cross-sectional thickness may be smooth or abrupt. The regions of different cross-sectional thickness may have different stiffness and / or durometer. The regions of different cross-sectional thickness may be formed from the same material or different materials. By selecting different materials and different cross-sectional thicknesses for the construction of the stretchable portion of the tube 3355, certain portions of the tube 3350 can be designed to be more flexible than other portions. As a result, portions of the tube 3350 that are positioned over portions of the patient anatomy where size variation between individuals is particularly large can be made more flexible than other portions to assist in fitting the patient interface to different patients. Additionally or alternatively, the stretchable portion of the tube 3355 may be designed to substantially maintain a predetermined minimum aperture area in use so that the impedance of the patient interface to the breathable gas flow can be configured to suit the respiratory treatment system (e.g., desired gas flow rate).

[0227] 8.3.3.3.6 Different pipe connection positions In certain forms of the present technology, the tube 3350 can be connected in multiple ways that allow the effective length of the fluid path between the connection port 3600 and the seal-forming structure 3100 to be adjusted.

[0228] In certain embodiments, each tube 3350 includes two or more separate tube members that can be fluidly connected at multiple locations to vary the length of the fluid pathway formed by the tube members. In one embodiment, a first tube member includes multiple ports along one side, and a second tube member includes one or more tubes that protrude from one side of the second tube member and mate with selected ports in the first tube member to fluidly connect the first and second tube members. The length of the tube 3350 formed by the first and second tube members can be adjusted by selecting which port the protruding tube on the second tube member is connected to. The ends of the first and second tube members adjacent to the connection ports and the protruding tubes are sealed to ensure that breathable gas passes only through each tube member and cannot be intentionally leaked. The ports on one side of the first tube member may also be equipped with automatic closing valves to prevent gas leakage when these ports are not connected to the second tube member.

[0229] In some forms of the present technology, multiple tubing connections are provided to the connection ports and / or cushion assembly 3150. For example, the plenum chamber 3200 may include two or more ports on each side to which the tubing 3350 can be selectively fluidly connected. The ports may be positioned such that adjusting which port the tubing is connected to changes the size of the patient the patient interface fits. For example, one port may be positioned such that it is closer to the patient's face in use than another port. Connecting to a tubing 3350 that is closer to the patient's face can accommodate a larger patient head than connecting the tubing 3350 to a port that is further away from the patient's face.

[0230] 8.3.3.3.7 Modifying the Patient Interface Loop In patient interfaces 3000 included in certain forms of the present technology, the positioning and stabilizing structure 3300 defines a loop configured to encircle a portion of the patient's head in use. In some forms of the present technology, the loop encircling a portion of the patient's head may be defined by, for example, one or more ties. For example, in the embodiment shown in FIG. 3A , the loop is defined by the tube 3350 and the cushion assembly 3150. It is within the loop created by these components that the patient's head is positioned when the patient interface 3000 is donned.

[0231] In some forms of the present technology, the positioning and stabilizing structure between the connection port 3600 and the seal-forming structure 3100 of the cushion assembly 3150 is adjusted by adjusting the size of this loop. Adjusting this loop allows the patient interface to be customized for different sized patients. In the above embodiments, we have shown how the loop size can be changed by changing the length of the tube 3350. Below, we will describe embodiments that use other mechanisms for adjusting the loop size.

[0232] 8.3.3.3.8 Loop adjustment mechanism In certain forms of the present technology, the patient interface 3000 includes a loop adjustment mechanism that can operate to adjust the position that holds two regions of the positioning and stabilizing structure 3300 together to adjust the loop size.

[0233] 5, the patient interface 3000 includes a strap 3390 connected between the tubes 3350. The strap 3390 is positioned toward the top of the patient interface 3000 below the connection port 3600 so that it passes over or near the top of the patient's head in use. The strap 3390 may be curved upward to accommodate the top of the patient's head. The strap 3390 may be formed from a flexible, rigid, or semi-rigid material.

[0234] In this embodiment, the loop of the patient interface 3000 that encircles the patient's head when the patient interface 3000 is worn is defined by the strap 3390, the cushion assembly 3150, and the portion of the tube 3350 connected between the strap 3390 and the cushion assembly 3150. The size of this loop can be adjusted by adjusting the strap. The patient interface includes a strap adjustment mechanism 3391. The strap adjustment mechanism 3391 allows the length of the strap 3390 to be adjusted. The strap adjustment mechanism 3391 can include an adjustable fastening attachment between two portions of the strap 3390. For example, one portion of the strap 3390 can pass through a loop that is attached to the end of the other portion of the strap 3390 and attached to the strap 3390 using hook-and-loop material. Alternatively, the two strap portions can be connected together using poppers or interlocking members that are connectable at multiple different locations. In another embodiment, the two portions of the strap 3390 each include a rack portion that engages with a pinion or teeth. The length of the strap 3390 can be adjusted by rotating this tooth. In another embodiment, the two portions of the strap 3390 can be telescopically slidable relative to one another and locked into place via an interlocking mechanism, magnets, or frictional engagement.

[0235] In yet another embodiment, one or both ends of the strap 3390 can be connected to the tube 3350 by an adjustable strap connection mechanism so that the location at which the strap 3390 is connected to one or both tubes 3350 can be changed.

[0236] 14 shows another form of the present technology. In this form, the patient interface 3000 includes a band 3395. The band 3395 is positioned around the upper end of the tube 3350 (i.e., the end of the tube closest to the connection port 3600). The band 3395 holds the tube 3350 at its upper end, and the position of the tube 3350 determines the size of the loop defined in part by the tube 3350 that surrounds a portion of the patient's head when the patient interface 3000 is worn. In use, the band 3395 can be moved along the tube 3350 to change the position at which it holds the tubes 3350 together, and therefore change the size of the loop defined by the patient interface 3000. Moving the band 3395 along the tube 3350 towards the connection port 3600 increases the size of the loop, allowing the patient interface to fit larger heads.

[0237] The increased level of friction between the band and the tube allows the band 3395 to be tightly secured around the tube 3350 so that the tube 3350 does not easily shift and become loose during use. For example, the band 3395 may be formed from rubber or other high friction material. Alternatively, the patient interface may include a mechanism for securing the band in position. For example, a plurality of ridges and / or protrusions may be provided on the outer edge of the tube 3350, and one or more detents may be provided on the inner surface of the band 3395 (to interlock with the ridges / protrusions on the tube 3350 and secure the band in place). These detents may be disengaged from the ridges / protrusions by a suitable mechanism to allow the band to be moved along the tube 3350 when desired.

[0238] In another embodiment, the upper portions of the two tubes 3350 are secured together by a clasp locker or zipper. For example, one row of teeth on the clasp locker may be attached on one tube 3350 and another row of teeth on the clasp locker may be attached on the other tube 3350. A slider is movable between the rows of teeth so that the position holding the two tubes 3350 together can be adjusted to change the size of the loop formed by the patient interface 3000, thereby accommodating patients with different head sizes.

[0239] 8.3.3.3.9 Loop Insert In certain forms of the present technology, the positioning and stabilizing structure 3300 includes one or more loop insertion members. These loop insertion members are configured to be secured to another portion of the patient interface 3000 (e.g., secured directly or indirectly to the tube 3350). The loop insertion member(s) are configured to be secured to at least partially define a loop that encircles a portion of the patient's head in use. The loop size can be adjusted to accommodate different sized patient heads by adjusting the size of the loop insertion member or by replacing the loop insertion member with a loop insertion member of a different size.

[0240] One form of the present technology is shown in Figure 15. In this form, the patient interface 3000 includes a loop insert member 3410. The loop insert member 3410 is connected to the underside of the tube 3350 and connection port 3600 and, in use, is positioned between the patient's head and the tube 3350 and connection port 3600. The loop insert member 3410 functions to vary the size of the loop that encircles a portion of the patient's head compared to the size of the loop that would be formed by the tube 3350 in the absence of the loop insert member.

[0241] The loop insert 3410 is removably attached to the tube 3350. As such, the loop insert 3410 can be removed and replaced with one or more replacement loop inserts 3411 a, 3411 b, or 3411 c. The replacement loop inserts 3411 a, 3411 b, or 3411 c can be different sizes than the loop insert 3410, allowing the size of the loop that encircles a portion of the patient's head to be adjusted by selecting the loop insert, thereby allowing the patient interface to be adapted for more comfort and a more secure fit to the patient. Removable loop inserts 3410 and 3411 are also advantageous for cleaning.

[0242] The loop insertion member may be made of a rigid or semi-rigid material that allows the tube 3350 to be spaced from the patient's head during use, thereby allowing the shape of the loop to vary around the patient's head. Materials with a certain degree of elasticity and flexibility may be used to increase comfort during wear (e.g., foam or gel materials). Because the loop insertion member comes into contact with the patient's hair or skin during wear, it is preferable that the loop insertion member be made of a material that can be easily cleaned.

[0243] The loop inserts 3410 and 3411 shown in FIG. 15 are generally U-shaped, with the apex of the "U" positioned above the patient's head below the connection port 3600 during use. This helps the patient interface conform to the shape of the top of the patient's head. In other embodiments, inserts of different shapes are used. For example, the inserts may include short, linear pads configured to contact smaller areas of the patient's head. Different sized replacement inserts 3411 may have different thicknesses, lengths, and / or levels of curvature. The patient-contacting surface of each insert may be the same or similar to conform to the shape of the patient's head, regardless of the insert used.

[0244] The loop insertion members 3410 and 3411 are attached to the tube 3350 by a fastening mechanism. In one embodiment, the fastening mechanism comprises hook and loop material attached to the underside of the tube 3350 and the top of the loop insertion members 3410 and 3411. In other embodiments, poppers, hemispheres, clasp lockers, or magnets are used to connect the loop insertion members 3410 and 3411 to the tube 3350.

[0245] In the embodiment of FIG. 15 , the patient interface 3000 includes a single loop insert member 3410, and the replacement loop insert member 3411 is a single or monolithic component. In other embodiments, multiple loop insert members may be attached to the tube 3350 at any time. For example, multiple loop insert members may be attached along the length of the tube 3350 to act as multiple spacers for spacing different portions of the patient's head from the tube 3350. In another embodiment, multiple loop insert members 3410 and replacement loop insert members 3411 may be attached to the tube 3350 at any time. For example, loop insert members of different sizes may be nested within one another. To accomplish this, the loop insert members 3410 and 3411 may be connected to one another, for example, using any of the loop insert member connection mechanisms described above.

[0246] 16 , the patient interface 3000 includes an inflatable loop insert 3420. The inflatable loop insert 3420 may comprise a bladder disposed on the interior surface of the tube 3350. The bladder has a sealable opening. By allowing air to pass in and out of the opening, the size of the bladder can be varied and therefore the size of the loop defined by the patient interface 3000 which surrounds a portion of the patient's head in use can be adjusted. In one embodiment, the patient interface includes a pump button. Repeated depression of the pump button introduces air into the bladder through a valve.

[0247] In the configuration shown in FIG. 16 , the patient interface includes a single U-shaped bladder 3420. This U-shaped bladder 3420 is connected to respective tubes 3350 on the top of the patient's head on either side of the patient's head. The thickness of the bladder 3420 may be greatest at the top of the patient's head to accommodate symmetrical movement of the tube 3350 away from the surface of the patient's head upon bladder inflation. In other embodiments, multiple inflatable bladders are mounted on the tube 3350. These inflatable bladders may be inflated collectively or individually. Individually inflatable bladders allow the patient to modify the fit of the patient interface as desired, for example, by inflating a bladder more on one side of the head than the other.

[0248] 8.3.3.3.10 Headgear tubing size adjustment size As described above, the positioning and stabilizing structure 3300 can be configured to be worn with the upper portion of the headgear tubing 3350 positioned in different positions to accommodate different patients. For example, the position of the connection port 3600 on the patient's head during use can vary within a range of anterior / posterior positions in the sagittal plane. The headgear tubing 3350 that fits circumferentially around the patient's head can be smaller if the upper portion of the headgear tubing 3350 is worn more anteriorly compared to if the headgear tubing 3350 is worn further posteriorly. In some forms, the positioning and stabilizing structure 3300 allows patients with larger head sizes to wear the upper portion of the headgear on their head in a more anterior (e.g., forward) position, thereby reducing the amount of length adjustment required by the adjustment mechanism 3360 to accommodate larger head sizes.

[0249] FIG. 3J shows three illustrations of patient interfaces 3000a, 3000b, and 3000c in accordance with one form of the present technology. Each illustration of the patient interface 3000 is shown in a different position on the patient's head for comparison. Patient interface 3000b is shown in solid lines in a centered position, while patient interfaces 3000a and 3000c are shown in phantom lines, mounted anteriorly and posteriorly, respectively. In each of the illustrations in FIG. 3J, the adjustment mechanism 3360 has substantially the same length. That is, the adjustment mechanism 3360 does not extend or retract between the illustrations labeled "a," "b," and "c." Without a change in the length of the adjustment mechanism 3360, patient interface 3000a (anterior position) is able to fit larger heads (shown in phantom) because it is mounted anteriorly. Similarly, patient interface 3000c (posterior position) is able to adequately fit smaller heads (shown in phantom) with the same length of adjustment mechanism 3360.

[0250] In one illustration in FIG. 3J, the patient is wearing the headgear in a centered position, as indicated by the reference numeral "b." In this centered position, the adjustment mechanism 3360b and the connection port 3600b are generally aligned vertically. The connection port 3600b is centered in the anterior-posterior axis. That is, the connection port 3600b is located in a central position, rather than in a generally anterior (e.g., anterior) position or a generally posterior (e.g., posterior) position. The connection port 3600b is located at a top point on the patient's head. The connection port 3600b may be located in the sagittal plane, aligned with the supra-ear point in a plane parallel to the coronal plane. The supra-ear point is shown in FIG. 2D.

[0251] In another illustration in FIG. 3J , as indicated by the reference numeral "a," the patient is wearing headgear tubing 3350a in a relatively forward (e.g., forward) position compared to the position of headgear tubing 3350b. In this configuration, connection port 3600a is located generally forward of adjustment mechanism 3360a. In this position, connection port 3600a is anterior to the supra-ear point. In another illustration in FIG. J , as indicated by the reference numeral "c," the patient is wearing headgear tubing 3350c in a relatively posterior (e.g., posterior) position compared to the position of headgear tubing 3350b. In this configuration, connection port 3600c is located generally posterior to adjustment mechanism 3360c. In this configuration, connection port 3600c is posterior to the supra-ear point.

[0252] When worn in the position shown by headgear 3300a in Figure 3J, the headgear tubing 3350a generally fits around a smaller circumference of the patient's head, allowing the positioning and stabilizing structure 3300 to be worn in a relatively forward position, accommodating patients with larger heads (shown in phantom). Similarly, when worn in the position shown by positioning and stabilizing structure 3300c in Figure 3J, the headgear tubing 3350c generally fits around a larger circumference of the patient's head, allowing the positioning and stabilizing structure 3300 to be worn in a relatively posterior position, accommodating patients with smaller heads (shown in phantom). The positioning and stabilizing structure 3300 can be worn in a continuous range of positions between a generally anterior position and a generally posterior position, depending on factors such as patient head size, head shape, and personal preference. In some forms, the positioning and stabilizing structure 3300 of the present technology is configured to be worn such that the connection port 3600 is located at the top of the head in use at a position approximately 20 mm forward (e.g., forward) from the center position and approximately 20 mm rearward (e.g., rearward) from the center position. In some forms of the present technology, the upper part of the headgear tube 3350 (e.g., the section above the rear strap 3310) is configured to flex, bend, or move in a forward or rearward direction (with substantially no corresponding movement in the lower part or non-adjustable tube section 3363 (e.g., the section below the rear strap 3310)). In other forms of the present technology, the upper and lower parts may move together (although not necessarily to the same extent). The rear strap 3310 may be configured to avoid or resist movement of the non-adjustable tube section 3363. For example, moving the top of the headgear tube 3350 forward onto the patient's head (without loosening the rear strap 3310) may require the top of the headgear tube 3350 to move more compared to the non-adjustable tube portion 3363.

[0253] Aside from being able to separately wear the positioning and stabilizing structure 3300 in different forward / backward positions, in some forms of the present technology, a headgear tubing adjustment mechanism 3360 allows the positioning and stabilizing structure 3300 to fit different sized heads. The headgear tubing adjustment mechanism 3360 may be configured to allow a predetermined amount of length adjustment of the headgear tubing 3350. The amount of length adjustment of the headgear tubing 3350 may be determined at least in part based on a range of head sizes that the positioning and stabilizing structure 3300 is configured to accommodate. In some forms of the present technology, the adjustment mechanism 3360 may allow the length of the headgear tube 3350 to be increased by an amount between approximately 10 mm and 50 mm on either side of the positioning and stabilizing structure 3300. In some forms of the present technology, the length increase may be by an amount of 20 mm to 40 mm on either side. In some forms of the present technology, the length increase that occurs is substantially any one of 25 mm, 30 mm, 35 mm, or 40 mm on either side.

[0254] 3K includes a positioning and stabilizing structure 3300. The positioning and stabilizing structure 3300 has a headgear tube 3350 and a headgear tube adjustment mechanism in a first configuration designated by reference numeral 3360. The adjustment mechanism 3360 is also shown in phantom in a second configuration and designated by reference numeral 3360'. In the first configuration of the adjustment mechanism 3360, the headgear 3300 fits around a patient with one size head, and in the second configuration of the adjustment mechanism 3360', the headgear 3300 fits around a patient with a larger head. In this form of the technology, the adjustment mechanism 3360' allows the length of the headgear tube 3350 to be extended to fit larger head circumferences. As shown in FIG. 3K, the adjustment mechanism 3360 / 3360′ allows the headgear to be worn in a central position (e.g., the connection port 3600 / 3600′ is centered over the top point of the head rather than in front or behind) while being able to adjust (or be adjusted) the headgear to accommodate different head sizes.

[0255] In some forms of the present technology, the adjustment mechanism 3360 also enables the length of the headgear tube 3350 to be adjusted when the headgear 3300 is mounted at the front position, the center position, and / or the rear position. The patient interface 3000 shown in FIG. 3L includes the headgear 3300. The headgear 3300 is mounted at three positions on the patient's head as indicated by reference numerals with "a", "b", and "c". The positioning and stabilization structure 3300a is mounted at the front position, the positioning and stabilization structure 3300b is mounted at the center position, and the positioning and stabilization structure 3300c is mounted at the rear position. That is, the connection port 3600a is at the front position on the patient's head, the connection port 3600b is at the center position, and the connection port 3600c is at the rear position. At the front position, the headgear tube 3350a fits around a smaller circumference of the patient's head compared to the circumference around which the headgear tube 3350b fits around the center position. To accommodate this smaller circumference, by providing the adjustment mechanism 3360a at the front position, it becomes possible to reduce the length of the headgear tube 3350 (or reduce the elongation). At the rear position, the circumference of the patient's head around which the headgear tube 3350c fits is larger than the circumference at the center position. To accommodate this larger circumference, the adjustment mechanism 3360c makes it possible to increase the length of the headgear tube 3350 compared to its length at the center position.

[0256] The combination of the different positions in which the positioning and stabilizing structure 3300 can be worn and the different amounts of length adjustment allowed by the adjustment mechanism 3360 provides a greater variety of adjustment options for the patient. This variety may allow the positioning and stabilizing structure 3300 to accommodate a wider range of head shapes and sizes (without undue discomfort) while still allowing the seal-forming structure 3150 to adequately seal against the patient's face. In some embodiments, the adjustment mechanism 3360 allows for a smaller amount of length adjustment because patients with larger head sizes can wear the upper part of the headgear tubing 3350 in a more forward position rather than relying solely on the adjustment mechanism 3360 to accommodate larger head sizes. In other embodiments, the adjustment mechanism 3360 allows for a larger amount of length adjustment because patients with larger head sizes can wear the upper part of the headgear tubing 3350 further forward, allowing the patient interface 3000 to fit a wider range of head sizes.

[0257] 8.3.3.4 Headgear tubing adjustment mechanism location It is generally desirable to avoid features of the patient interface that cause patient discomfort. As such, the patient interface may be designed with some components that come into contact with the patient's skin, and the components that actually come into contact with the patient's skin may be soft and / or smooth. The cheek area is known to be a source of patient discomfort when wearing patient interfaces.

[0258] The mechanism enabling adjustment of the positioning and stabilizing structure described above may include features that cause discomfort to the patient when in contact with the patient's face or head (particularly the cheek region). Therefore, the positioning and stabilizing structure included in certain forms of the present technology is configured so that the adjustment mechanism, or portions thereof, do not come into contact with the patient's skin or hair region when the patient interface is worn (e.g., not in contact with the patient's face or not in contact with the patient's cheek region). In some forms of the present technology, the adjustment mechanism is positioned above the patient's ear (i.e., above the supra-ear point of the patient's head or near the top of the patient's head). In these forms of the present technology, the headgear tube includes a non-adjustable headgear tube. This non-adjustable headgear tube is positioned adjacent to the patient's face when in use (i.e., positioned so that the non-adjustable headgear tube may come into contact with the patient's face when the patient interface is in use). For example, in some forms, the non-adjustable headgear tube is positioned adjacent to the patient's cheek region when worn. In some forms of the present technology, only the non-adjustable headgear tubes are adjacent to the cheek area of the patient, below the supra-ear point of the patient's head, or cover the maxillary area of the patient's head.

[0259] It is understood that a non-adjustable headgear tube is a portion that is specifically configured to be dimensionally adjusted in use (i.e., the adjustment mechanism does not form part of the non-adjustable headgear tube). This does not exclude that the non-adjustable headgear tube may be dimensionally adjustable, for example, when excessive force is applied. However, the position of the non-adjustable headgear tube may be adjusted in use. In some forms of the present technology, the non-adjustable headgear tube may be substantially non-adjustable in axial length, but may also be adjustable in other manners, such as by flexing, bending, straightening, etc. For example, as shown in FIG. 3L, non-adjustable headgear tubes 3363a, 3363b, and 3363c are configured to bend or curve to different extents, such that the different amounts of extension allowed by adjustment mechanisms 3360a, 3360b, and 3360c facilitate different positions in which the positioning and stabilizing structure 3300 is worn on the head.

[0260] It can also be useful to locate the adjustment mechanism outside the patient's field of vision to avoid any feeling of claustrophobia or obstructed vision.

[0261] 3A, 3B, 3C, 3D, 3E and 3F, for example, the bellows portion 3362 is positioned on either side of the patient's head, between ear or ear height and the crown or top of the head of the level head and non-adjustable headgear tube 3363. The level head and non-adjustable headgear tube 3363 forms the lower end of the headgear tube (i.e., the lower end when worn by the patient) and is positioned adjacent to (or over) the patient's cheek area when worn. Other examples of non-adjustable headgear tubes 3363 are shown in Figures 5, 7A, 7B, 7C and 17.

[0262] In certain forms of the present technology, the non-adjustable headgear tube 3363 is configured to assist in maintaining a proper seal between the cushion assembly 3150 and the patient's face during use of the patient interface 3000. To do this, the flexibility (or stiffness) of the non-adjustable headgear tube 3363 may need to be selectable so that it is flexible enough to accommodate some movement during use and some variation in the position in which an individual patient wears the patient interface 3000, yet stiff enough so that the non-adjustable headgear tube 3363 does not easily deform during use.

[0263] The rear headgear straps 3310 stabilize the headgear tube 3350 on the patient's head, but allow the lower end of the headgear tube 3350 to move more freely, especially at a point relatively far from where the rear headgear straps 3310 contact the headgear tube 3350. If the lower end of the headgear tube 3350 is too flexible, the cushion assembly 3150 will tend to rotate forward, away from the patient's face, thereby disrupting the seal. Increasing the stiffness of the lower end of the headgear tube 3350 (i.e., the non-adjustable headgear tube section 3363 in the form of the present technology shown in Figures 3A, 3B, 3C, 3D, 3E, 3F, 5, 7A, 7B, 7C and 17) can reduce the effects of such forward rotation. For the purposes of this discussion, the lower ends of the headgear tubes 3350 are considered to be the portions of the headgear tubes 3350 that are located below the point where the rear headgear straps 3310 connect to each headgear tube 3350 (i.e., below the patient interface 300 when the patient is fitted with the patient) because this point is stable on the patient's head and can therefore act as a pivot point for any movement of the headgear tubes 3350 below this point. It is understood that if other headgear strap arrangements are used, the location of the effective pivot point will be different.

[0264] For similar reasons, in some forms of the present technology it may be advantageous to leave the lower end of the headgear tube 3350 free from any adjustment mechanism. If a concertina section were provided on the headgear tube 3350, for example, at the point where the rear headgear straps 3310 connect to the headgear tube 3350, the concertina section would tend to buckle and bend during movement and act as a natural pivot, which could cause the cushion assembly to move and disrupt the seal with the patient's face.

[0265] Furthermore, providing an adjustment mechanism 3360 at the top of the headgear tubes 3350 (which for the purposes of this discussion will be considered to be the portion of the headgear tube 3350 located above (i.e., above) the point where the rear headgear straps 3310 connect to each headgear tube 3350) helps to decouple the upper and lower sections of the headgear tube 3350 so that movement of the upper section (due to use or due to variations in the position of the patient interface 3000 on the patient's head) does not place excessive force on the cushion assembly 3150 which could cause an impaired seal with the patient's face. In particular, using an adjustment mechanism 3360 that allows the length of the headgear tube 3350 to be extended helps to avoid straightening the non-adjustable headgear tube section 3363 at the bottom end of the headgear tube 3350 because this type of adjustment mechanism 3360 allows the bottom end of the patient interface 3000 to be moved up and down (i.e., downwards and upwards) relative to the patient's head. Also, if the non-adjustable headgear tube 3363 becomes too straight and / or elongated, the cushion assembly 3150 may rotate forward, thereby disrupting the seal with the patient's face.

[0266] In some forms of the present technology, the radius of curvature of the non-adjustable headgear tube section 3363 (or the lower end of the headgear tube 3350) also affects the level of movement of the upper end of the headgear tube 3350. The larger the radius of curvature, the greater the separation effect between the upper and lower ends of the headgear tube 3350, allowing the upper end of the headgear tube 3350 to move without causing significant forward rotation of the cushion assembly 3150 and a resulting loss of seal.

[0267] In some forms of the present technology, locating the adjustment mechanism 3360 at the top of the headgear tube 3350 near the connection port 3600 can help reduce tube drag on the head by allowing the connection to be separated through the extension and flexion provided by the adjustment mechanism.

[0268] In some forms of the present technology, if the adjustment mechanism 3360 is located on an upper portion of the headgear tube 3350 spaced from the cushion assembly 3150, the effect on the cushion assembly 3150 due to differential extension of the headgear tube 3350 can be reduced. For example, it is possible to reduce the effect of an imbalance in the extension of the adjustment mechanism 3360 on either side of the patient's head and / or any force applied from the adjustment mechanism 3360 to either side of the patient's head. If such an effect exists, the seal formed by the cushion assembly 3150 on the patient's face can be compromised.

[0269] In other forms of the present technology, the adjustment mechanism may be located near the cushion assembly 3150 of the patient interface and spaced from the patient's face due to the size of the plenum chamber and the location of the port where the tube 3350 connects from the lower end of the tube 3350 to the plenum chamber at a location away from the patient's skin (and thus the adjustment mechanism). The form of the present technology shown in Figure 10B is one such example of a patient interface 3000 where the adjustment mechanism is spaced from the patient's face in use. 8.3.3.5 Headgear tubing actuation mechanism

[0270] In certain forms of the present technology, the positioning and stabilization structure 3300 includes a biasing mechanism. This biasing mechanism functions to propel the seal-forming structure 3100 towards the patient's face (i.e., towards the area surrounding the patient's airway inlet where the seal-forming structure 3100 seals) during use. Thus, the biasing mechanism serves to assist in providing a good seal between the seal-forming structure 3100 and the patient's face during use of the patient interface 3000, and in promoting the retention of the seal when the patient interface supplies positive pressure gas to the patient. In some forms of the present technology, the biasing mechanism acts on (i.e., applies a biasing force to) the adjustment mechanism 3360. When the plenum chamber 3200 is pressurized, the cushion assembly 3150 of the patient interface 3000 tends to move away from the patient's face. The biasing mechanism having the function of biasing or propelling the cushion assembly 3150 towards the patient's face invalidates this tendency to maintain the seal.

[0271] In some forms of the present technology, the biasing mechanism has the function of applying a biasing force along at least a portion of the length of the headgear tube 3350 to propel the seal-forming structure towards the inlet of the patient's airway during use. In such forms, the headgear tube 3350 or a portion thereof is in a tensioned state during use. In some forms, the biasing mechanism is included as part of the headgear tubing 3350, and in other forms, the biasing mechanism is separate from the headgear tubing 3350.

[0272] The biasing mechanism may also assist in automatically adjusting the patient interface to fit a particular patient's head.

[0273] 8.3.3.5.1 Magnitude of the force added from the biasing mechanism The biasing mechanism is preferably configured to apply sufficient inward force (i.e., towards the patient's airway opening) to maintain a good seal in use while avoiding the application of excessive force, which may cause the seal-forming structure 3100 to compress and change its geometry, causing portions of the structure to move away from the patient's face and causing gas to leak from the seal-forming structure. Additionally, avoiding excessive force from the patient interface on the patient's face promotes comfort and avoids red marks, abrasions, or sweating on the patient's face.

[0274] In some forms of the present technology, an acceptable force provided from the biasing mechanism can be 0.5-4 N on each side of the positioning and stabilizing structure 3300. In some forms, the acceptable force can be 1-3.5 N. A force of approximately 2 N can be considered acceptable. In some forms of the present technology, the positioning and stabilizing structure 3300 is configured to support a seal-forming structure 3100 in the form of a full-face or oronasal cushion assembly (e.g., the seal-forming structure 3100 shown in FIGS. 4A-4E). In some forms of the present technology, the full-face or oronasal seal-forming structure 3100 is heavier than other forms of seal-forming structures (e.g., nasal cradles or nasal pillows) due to its larger size. The positioning and stabilizing structure 3300 is configured to bias the cushion assembly 3150 into the patient's face with a force high enough to maintain an effective seal without causing undue discomfort, while providing a correspondingly higher biasing force to absorb the weight or counteract the traction of the heavier seal-forming structure 3100. Additionally, when a patient relaxes or moves their jaw (known as "gazing"), the full face or oral-nose seal-forming structure 3100 may experience a downward (e.g., downward) force. The positioning and stabilizing structure 3100 may also be configured to account for the effects of gazing by counteracting the downward force experienced during gazing.

[0275] In some forms of the present technology, the positioning and stabilizing structure 3300 is configured to interchangeably receive seal-forming structures of different sizes (e.g., a relatively small or lightweight seal-forming structure (e.g., a nasal cradle cushion assembly) and a relatively large or heavy seal-forming structure (e.g., an oral-nasal cushion assembly)). The positioning and stabilizing structure may include a biasing mechanism configured to support both types of seal-forming structures by applying a sufficiently strong biasing force (but not excessive enough to cause discomfort) to either type of seal-forming structure.

[0276] In some forms of the present technology, the positioning and stabilizing structure 3300 is configured to provide a range of forces sufficient to maintain an effective seal against the nasal cradle or full face mask (but not excessive to cause discomfort) in multiple adjustment configurations.

[0277] In some forms of the present technology, a biasing mechanism is configured to apply a force to the headgear tube 3350, or a portion thereof, to urge the headgear tubing to fit around the patient's head. The biasing mechanism may be configured to provide a force within a predetermined range of magnitude. Such predetermined range may be limited to an amount that is comfortable for the headgear 3300 and maintains an adequate seal between the seal-forming structure 3100 and the patient's face. The biasing mechanism may be configured to urge the seal-forming structure 3100 into sealing contact with the patient's face with a force that is less than the minimum force required for adequate force; that is, this force may be equal to or greater than the minimum sealing force. The biasing mechanism may be configured to urge the headgear tubing 3350 to fit around the patient's head with a force that does not exceed a maximum force deemed comfortable by the patient; that is, this force may be equal to or less than the maximum comfortable force.

[0278] In some forms of the present technology, each headgear tube 3350 includes a force-extension characteristic resulting from the relationship between the extension of the headgear tube 3350 and the force applied from the biasing mechanism to the headgear tube 3350. Alternatively or additionally, the force-extension characteristic may result from the relationship between the force applied from the biasing mechanism to the headgear tube 3350 and the extension of the headgear tube 3350. It is understood that the term "extension" refers to the change in overall length of the headgear tube, and not the physical structure of any adjustment mechanism or manner in which the change in overall length of the headgear tube 3350 occurs.

[0279] In certain forms of the present technology, the biasing mechanism may provide a biasing force on the headgear tube 3350 that tends to return the headgear tube 3350, or a portion thereof, to a predetermined length (e.g., the length before adjustment by the adjustment mechanism). In some forms of the present technology, the biasing mechanism imparts a restoring force on the headgear tube 3350.

[0280] As described above, the adjustment mechanism 3360 of the patient interface 3000 according to some forms of the present technology allows for length adjustment of the headgear tube 3350. In some embodiments, when a relationship exists between the biasing force and the extension of the headgear tube 3350, when the headgear tube 3350 is extended to a first amount of extension (e.g., to a first extended length), the force applied from the biasing mechanism is equal to or greater than a minimum sealing force. Furthermore, when the headgear tube 3350 is extended to a second amount of extension (e.g., to a second extended length), the force applied from the biasing mechanism is equal to or less than a maximum comfort. Furthermore, when there is an extension amount between the first and second amounts of extension, the force applied from the biasing mechanism can be between a minimum sealing force and a maximum comfort.

[0281] In some forms of the present technology, the headgear tube 3350 may include a force-extension characteristic such that when the headgear tube 3350 is adjusted to a first amount of extension (e.g., to an amount of extension that provides at least a minimum sealing force from the biasing mechanism), the positioning and stabilizing structure 3300 can accommodate a predetermined minimum head size. Similarly, when the headgear tube 3350 is adjusted to a second amount of extension (e.g., to an amount of extension that no longer provides maximum comfort from the biasing mechanism), the positioning and stabilizing structure 3300 can accommodate a predetermined maximum head size. For extensions between the first and second amounts of extension, the positioning and stabilizing structure 3300 can accommodate head sizes between the minimum and maximum predetermined head sizes. The predetermined minimum head size can be, for example, a 5th percentile head size for a particular category of people, and the predetermined maximum head size can be, for example, a 95th percentile head size for a particular category of people. It is understood that other measurements / ranges may be used to determine the minimum and maximum head sizes that the positioning and stabilizing structure 3300 can accommodate.

[0282] The force-extension plot 6000 shown in Figure 3I shows the force-extension characteristic 6300 of the headgear tube 3350 of a patient interface 3000 in accordance with one form of the present technology. The horizontal extension axis 6100 and vertical force axis 6200 shown in the force-extension plot 6000 indicate the relationship between the length of the headgear tube 3350 and the resulting force applied from the biasing mechanism.

[0283] Three extensions of the headgear tube 3350 are shown on the extension axis 6100: a zero extension 6105, a first extension amount 6110 corresponding to the extension required to accommodate a 5th percentile head size (e.g., a predetermined minimum head size), and a second extension amount 6120 corresponding to the extension required to accommodate a 95th percentile head size (e.g., a predetermined maximum head size). Two force magnitudes are shown on the force axis 6200: a minimum sealing force 6210 and a maximum comfort 6220.

[0284] In this exemplary form of the present technology, the headgear tube 3350 includes a force-extension profile 6300 such that the force applied by the biasing means is above the minimum sealing force 6210 and below the maximum comfort force 6220 throughout the range of extension between the first amount of extension 6110 and the second amount of extension 6120. That is, an adequate seal can be maintained throughout the range of accommodating head sizes without causing discomfort due to excessive biasing force.

[0285] It is understood that in some forms of the present technology, the relationship between extension and biasing force may not be directly proportional. For example, in some forms of the present technology, there may be a relatively large increase in force during the initial extension phase, but there is little variation in force over the range of extension required to accommodate the minimum and maximum predetermined head sizes. Regardless of how the force changes within the limits, an effective seal can be achieved without discomfort by keeping the force magnitude between minimum sealing force and maximum comfort throughout the range of extension between the minimum and maximum head sizes.

[0286] 8.3.3.5.2 Biasing mechanism location In some forms of the present technology, a biasing mechanism functions between the seal-forming structure 3100 and the connection port 3600. For example, the biasing mechanism may include a component of the patient interface connected between the seal-forming structure 3100 and the connection port 3600 and urge the seal-forming structure 3100 generally toward the connection port 3600 and / or longitudinally along the length of the tube 3350.

[0287] 8.3.3.5.3 Biasing mechanism configuration The biasing mechanism can take multiple forms. In some forms of the present technology, the biasing mechanism is a separate mechanism from the adjustment mechanism, allowing for adjustment of the positioning and stabilizing structure as described above. In such forms, the adjustment mechanism allows for adjustment of the patient interface to fit the patient's head, while the biasing mechanism provides the function of urging the sheet against the patient's face. In other forms, the biasing mechanism and the adjustment mechanism are provided at least in part by the same features as the patient interface, with the adjustment and biasing described above being different functions performed by these same features.

[0288] In some forms of the present technology, the biasing mechanism includes a resilient or elastic member or assembly. In some forms, the resilient or elastic member or assembly is connected between the seal-forming structure 3100 and the connection port 3600. For example, the resilient or elastic member or assembly is included as part of or connected to the tube 3350 or connection assembly between the tube 3350 and the plenum chamber 3200 and / or the connection assembly between the tube 3350 and the connection port 3600.

[0289] 3A, 3B, 3C, 3D and 3E, the biasing mechanism includes a bellows tube 3362. The bellows tube 3362 is configured to be biased to a compressed position such that the bellows tube 3362 functions to pull the seal-forming structure 3100 against the patient's face in use.

[0290] In some forms of the present technology, there is a relationship between the extension of the bellows tube 3362 and the restoring force applied to the headgear tube 3350. This restoring force can be tension within the bellows tube 3362. The bellows tube 3362 can have force-extension characteristics similar to those described in connection with FIG.

[0291] The bellows tube 3362 may be designed to extend to a first amount of extension that allows the positioning and stabilizing structure 3300 to accommodate a predetermined minimum head size (e.g., a 5th percentile head size) and to a second amount of extension that allows the positioning and stabilizing structure 3300 to accommodate a predetermined maximum head size (e.g., a 95th percentile head size). The bellows tube 3362 may be designed so that at the first amount of extension, the tension exceeds the minimum force required to create a proper seal of the seal-forming structure 3100 against the patient's face. At the second amount of extension, the bellows tube 3362 may be designed so that the tension does not exceed a maximum force deemed comfortable by the patient. In this way, the positioning and stabilizing structure 3300 can accommodate a range of head sizes, thereby creating an adequate seal throughout the entire range without causing discomfort due to force.

[0292] In certain forms of the present technology, the bellows tube 3362 may include a bellows profile that provides the force-extension characteristics of the bellows tube 3362 as described above. As shown in FIG. 3G, the bellows tube 3362 may include walls. The walls have a bellows profile with a repeating wavy pattern in which the inner valleys are curved and the outer peaks are flat. The flat outer peaks provide a smooth, flat surface that can be comfortably positioned against the patient's head. The bellows tube 3362 may include multiple ribs formed in the wall of the headgear tube 3350 to form the bellows. These ribs may extend inward as shown in FIG. 3G. Alternatively or additionally, the bellows tube 3362 may include multiple grooves.

[0293] The profile of the corrugated tube 3362 can be varied to achieve desired force-extension characteristics. For example, the rib pitch (e.g., the peaks / valleys of the corrugations) can be reduced to provide a more compliant corrugated tube 3362 (e.g., generally greater extension at a given force). Additionally, the rib height (e.g., the amplitude of the corrugations) can be increased to provide a more compliant corrugated tube 3362. Alternatively, increasing the rib pitch or decreasing the rib height can provide a less compliant corrugated tube 3362.

[0294] Additionally or alternatively, for improved compliance, a longer corrugated tube 3362 may be provided. This may be possible, for example, by increasing the number of ribs formed in the wall of the corrugated tube 3362.

[0295] Additionally or alternatively, the wall thickness of the bellows tube portion 3362 may be reduced to provide a more extensible bellows tube portion 3362, or the wall thickness of the bellows tube portion 3362 may be increased to provide a stiffer bellows tube portion 3362.

[0296] Additionally or alternatively, the material forming the bellows tube 3362 may be selected to assist in providing predetermined force-elongation characteristics. In one form of the present technology, the material is 50 durometer silicone. Other materials and / or durometers may also be selected (e.g., 40 durometer silicone).

[0297] Additionally or alternatively, to achieve different amounts of extension, different bellows profile shapes may be used for the bellows tube 3362. For example, a more extensible bellows tube 3362 may be obtained using a bellows tube 3362 in which the walls defining the profile are generally more folded.

[0298] The configuration of the corrugated tube 3362 may vary along its length. In some forms of the present technology, for example as shown in FIG. 3G , the rib height decreases along the length of the corrugated tube 3362 in a direction away from the connection port 3600 (e.g., toward the non-adjustable headgear tube 3363). The rib height may vary within a range, for example, 0-6 mm, 0-5 mm, 0-4 mm, 1-5 mm, etc. Alternatively, the rib height may be constant, for example, at a value of 2 mm, 3 mm, 4 mm, etc. The wall thickness may be substantially constant along the length of the corrugated tube 3362 or may vary. In some forms of the present technology, the wall thickness may be within a range of 0.5 mm to 1.2 mm (e.g., 0.6 mm to 1 mm or 0.8 mm). The rib pitch may be within a range of 3.5 to 5 mm (e.g., 3.8 to 4.5 mm or 4.2 mm).

[0299] In other forms of the present technology, the shape and configuration of the bellows tube portion 3362 differs from the parameters exemplified above.

[0300] 13, the relatively stretchable portion of the tube 3355 is stretchably or elastically deformable and has a tendency to return to a non-stretched state. Thus, in use, the relatively stretchable portion of the tube 3355 functions to pull the seal-forming structure 3100 into the patient's face. Alternatively, the tube 3350 may be formed entirely from an elastic material that has a tendency to return to a non-stretched state when stretched.

[0301] Another form of the present technology is shown in Figure 17. In this form, the patient interface 3000 includes one or more elastic sleeves 3340 covering the tube 3350. It will be understood that the elastic sleeve 3340 may only partially cover the tube 3350, for example, holes may be provided in the sleeve 3340 as described below. Alternatively, the headgear tube may be considered to include both an elastic sleeve and an inner gas delivery conduit with an elastic sleeve covering the inner gas delivery conduit. The elastic sleeve 3340 may be formed from any stretchable, elastic or extensible material (e.g., elastic fabrics such as elastane have a tendency to return to their original size and shape when stretched).

[0302] The elastic sleeve 3340 covers the tubes 3350 which each contain a corrugated tube 3362. The corrugated tubes 3362 may or may not be biased to a compressed position. The presence of the corrugated tubes 3362 allows the length of the tubes 3350 to be adjusted to allow the patient interface 3000 to fit an individual patient, while the elastic sleeve 3340 functions to draw the seal-forming structure 3100 of the cushion assembly 3150 into the patient's face to improve the seal.

[0303] The elastic sleeve 3340 may comprise a single sheet of elastic material, or may be formed from multiple sheets of elastic material connected together (e.g., sewn or glued). Alternatively, the patient interface 3000 may include multiple separate elastic sleeves, for example, one sleeve covering each tube 3350.

[0304] The elastic sleeve 3340 may include openings that allow portions of the patient interface to pass through the sleeve. For example, the elastic sleeve may include rear or side openings 3342 through which the rear headgear straps 3310 connect to the tubes 3350. Additionally or alternatively, the sleeve may include a top opening 3343 through which the air circuit 4170 may connect to or through which the connection port 3600 may protrude. The headgear tubes 3350 may contact the patient's head through the openings 3342.

[0305] The corrugated tube portion 3362 of the tube 3350 can cause discomfort if it comes into contact with the patient's skin or hair during use. Even if the corrugations do not actually cause any discomfort, the patient may find the corrugated portion unsightly or uncomfortable to wear in the future, which is undesirable. Covering the corrugated portion 3362 with an elastic sleeve 3340 avoids these problems. To provide comfort benefits, a non-elastic sleeve may be used in some embodiments. This sleeve has the advantage of being made of a soft material that is not uncomfortable when in contact with the patient.

[0306] The elastic sleeve 3340 may come into contact with the patient's hair or skin during use and is therefore prone to becoming soiled with the patient's natural oils. As such, it may be advantageous for the elastic sleeve 3340 to be formed from a material such as a fabric that is easily washable. To facilitate cleaning of the elastic sleeve 3340 by the patient, the elastic sleeve 3340 may be detachable from the rest of the patient interface 3000. For example, the sleeve may include a mechanism for securing the sleeve onto the tube 3350 that can be disengaged when the sleeve is removed. For example, the elastic sleeve 3340 may surround the tube 3350 and connect to itself with a clip, popper, hook-and-loop material, or other suitable fastener.

[0307] In some forms of the present technology, the elastic sleeve 3340 is formed from a material or fabric that helps wick moisture away from the patient's face, which can help maintain comfort when the patient sweats while wearing the patient interface.

[0308] In other forms of the present technology, the elastic sleeve may include tubing or other portions of the positioning and stabilizing mechanism, including other adjustment mechanisms as described above. The sleeve may be advantageous in covering mechanisms or components that may have a complex or medical appearance that discourages wearing of the patient interface.

[0309] In another form of the present technology, a telescopically adjustable headgear tube may include a biasing mechanism that functions to compress a telescopically movable headgear tube portion (e.g., a spring).

[0310] An advantage of a manually adjustable adjustment mechanism that also provides a biasing force (e.g., adjustment mechanism 3360 shown in FIG. 7C) is that it can support both relatively heavy and relatively light seal-forming structures in a modular design (i.e., in a manner that allows for different types of seal-forming structures to be interchanged). For example, if the cushion assembly 3150 of the embodiment shown in FIG. 7C is replaced with a heavier oral-nasal cushion assembly, the patient can manually adjust the length of the headgear tube 3350 to a shorter configuration to offset the weight of the oral-nasal cushion and allow the cushion to sag downward or be pressed downward by movement of the patient's jaw.

[0311] 8.3.4 Ventilation In one form, the patient interface 3000 includes a vent constructed and arranged to allow a continuous flow or washout of exhaled gases (e.g., carbon dioxide (CO2) from within the plenum chamber to the ambient) thereby reducing the risk of the patient rebreathing such gases. That is, the vent allows the patient's exhaled CO2 to flow out of the patient interface. The vent is sized and shaped to maintain therapeutic pressure within the plenum chamber.

[0312] The ventilation part in one embodiment according to the present technology includes a plurality of holes (for example, about 20 to about 80 holes, or about 40 to about 60 holes, or about 45 to about 55 holes).

[0313] The vent may be located within the plenum chamber 3200. Alternatively, the vent may be located within another portion of the patient interface (e.g., the tube 3350 fluidly connecting the plenum chamber 3200 and the connection port 3600).

[0314] 8.3.5 Decoupling structure(s) In one form, the patient interface 3000 includes at least one decoupling structure (e.g., a swivel or bulb) that may be located at or near the connection port 3600 to allow the conduit of the air circuit 4170 to move relative to the patient interface 3000 and reduce the risk of destabilizing the seal between the seal-forming structure 3100 and the patient's face.

[0315] 8.3.6 Connection Port The connection port 3600 allows for connection to the air circuit 4170. In the embodiments of the present technology shown in FIGS. 3 and 5-17, for example, the connection port is located on the patient's head when the patient interface 3000 is worn. In other embodiments, the connection port is configured to be located near the top, side, or back of the patient's head when in use. Patient interfaces where the connection port is not located in front of the patient's face can be advantageous as some patients find conduits connecting to a patient interface in front of the face unsightly and uncomfortable. For example, conduits connecting to a patient interface in front of the face can be prone to entanglement with bedding, especially if the conduit extends downward from the patient interface when in use.

[0316] 8.3.7 Forehead support In one form, the patient interface 3000 includes a forehead support which, in use, contacts the patient's forehead region to support the patient interface on the patient's head and assist in maintaining sealing contact of the sealing structure with the patient's face.

[0317] 8.3.8 Anti-asphyxiation valves In some forms of the present technology, the patient interface 3000 is constructed and arranged to allow the patient to breathe ambient air in the event of a power outage, hi one form, the patient interface 3000 includes an anti-asphyxiation valve.

[0318] 8.3.9 Ports In one form of the present technology, the patient interface 3000 includes one or more ports that allow access to the volume within the plenum chamber 3200. In one form, this allows a clinician to provide supplemental oxygen. In one form, this allows a property of the gas (e.g., pressure) within the plenum chamber 3200 to be directly measured.

[0319] 8.4 RPT Devices An RPT device 4000 (as shown in FIG. 4A ) in accordance with one aspect of the present technology includes mechanical and pneumatic components 4100, electrical components 4200, and is configured to execute one or more algorithms 4300. The RPT device may have an outer housing 4010. The outer housing 4010 is formed by two portions, an upper portion 4012 and a lower portion 4014. Further, the outer housing 4010 may include one or more panel(s) 4015. The RPT device 4000 includes a chassis 4016 that supports one or more internal components of the RPT device 4000. The RPT device 4000 may include a handle 4018.

[0320] The air pressure path of the pneumatic RPT device 4000 may include one or more air circuit items (e.g., an inlet air filter 4112, an inlet muffler 4122, a pressure generator 4140 (e.g., a blower 4142) capable of supplying air at positive pressure, an outlet muffler 4124) and one or more transducers 4270 (e.g., a pressure sensor 4272 and a flow sensor 4274).

[0321] One or more of the air path items may be disposed within a removable, unitary structure referred to as a pneumatic block 4020. The pneumatic block 4020 may be disposed within the outer housing 4010. In one form, the pneumatic block 4020 is supported by or formed as part of the chassis 4016.

[0322] The RPT device 4000 can have a power supply 4210, one or more input devices 4220, a central controller 4230, a therapy device controller 4240, a pressure generator 4140, one or more protection circuits 4250, a memory 4260, a transducer 4270, a data communication interface 4280, and one or more output devices 4290. The electrical components 4200 can be mounted on a single printed circuit board assembly (PCBA) 4202. In an alternative, the RPT device 4000 can include more than one PCBA 4202.

[0323] 8.4.1 RPT Device Mechanical and Pneumatic Components The RPT device may include one or more of the following components in an integral unit: In an alternative, one or more of the following components may be arranged as their own separate units.

[0324] 8.4.1.1 Air filters An RPT device in accordance with one form of the present technology may include an air filter 4110 or multiple air filters 4110.

[0325] In one form, the inlet air filter 4112 is located at the beginning of the air pressure path upstream of the pressure generator 4140 .

[0326] In one form, an outlet air filter 4114 (eg, an antibacterial agent) is located between the outlet of the pneumatic block 4020 and the patient interface 3000.

[0327] 8.4.1.2 Pressure generator In one form of the present technology, the pressure generator 4140 that generates the air flow or supply at positive pressure is a controllable blower 4142. For example, the blower 4142 may include a brushless DC motor 4144 with one or more impellers housed within a volute. The blower may deliver the air supply at a rate of, for example, up to about 120 liters / minute, at a positive pressure ranging from about 4 cmH2O to about 20 cmH2O, or in other forms up to about 30 cmH2O. The blower may be described in any one of the following patents or patent applications, which are incorporated herein by reference in their entirety: U.S. Patent No. 6,223,999; U.S. Patent No. 6,223,999; U.S. Patent No. 6,223,999; and U.S. Patent No. 6,223,999.

[0328] The pressure generator 4140 is under the control of the therapy device controller 4240 .

[0329] In other forms, pressure generator 4140 can be a piston-driven pump, a pressure regulator connected to a high pressure source (eg, a compressed air reservoir), or a bellows.

[0330] 8.4.1.3 Air circuits An air circuit 4170, according to one aspect of the present technology, is a conduit or tube constructed and arranged such that, in use, air flow travels between two components (e.g., the RPT device 4000 and the patient interface 3000).

[0331] In particular, the air circuit 4170 may be fluidly connected to the outlet of the RPT device 4000 and the patient interface 3000. The air circuit may be referred to as an air delivery tube or conduit. In some cases, there may be separate limbs of the circuit for inhalation and exhalation. In other cases, a single limb is used.

[0332] In some forms, the air circuit 4170 may include one or more heating elements configured to heat the air in the air circuit (e.g., to maintain or increase the air temperature). The heating elements may take the form of a heated wire circuit and may include one or more transducers (e.g., temperature sensors). In one form, the heated wire circuit may be spirally wound around the axis of the air circuit 4170. The heating elements may be in communication with a controller (e.g., central controller 4230). One example of an air circuit 4170 including a heated wire circuit is described in U.S. Patent Application Publication No. 2007 / 0129994, which is incorporated herein by reference in its entirety.

[0333] 8.5 Humidifier 8.5.1 Humidifier Overview In one form of the present technology, a humidifier 5000 is provided (for example as shown in FIG. 5A) for changing the absolute humidity of air or gas to be delivered to a patient relative to ambient air. Typically, the humidifier 5000 is used to increase the absolute humidity (relative to ambient air) and increase the temperature of the air stream before delivery to the patient's airways.

[0334] The humidifier 5000 may include a humidifier reservoir 5110, a humidifier inlet 5002 for receiving an airflow, and a humidifier outlet 5004 for delivering a humidified airflow. In some forms, such as shown in Figures 5A and 5B, the inlet and outlet of the humidifier reservoir 5110 may be the humidifier inlet 5002 and the humidifier outlet 5004, respectively. The humidifier 5000 may further include a humidifier base 5006. The humidifier base 5006 may be adapted to receive the humidifier reservoir 5110 and may include a heating element 5240.

[0335] 8.6 Glossary For purposes of this disclosure, in certain aspects of the technology, one or more of the following definitions may apply. In other aspects of the technology, other definitions may apply.

[0336] 8.6.1 General Air: In certain forms of the present technology, air may refer to atmospheric air, while in other forms of the present technology, air may refer to a combination of other breathable gases (e.g., oxygen-rich atmospheric air).

[0337] Atmosphere: In certain forms of the present technology, the term "atmosphere" should be taken to mean (i) that which is external to the treatment system or patient, and (ii) that which immediately surrounds the treatment system or patient.

[0338] For example, the ambient humidity for a humidifier may be the humidity of the air immediately surrounding the humidifier (e.g., the humidity inside the room where the patient is sleeping), which may differ from the humidity outside the room where the patient is sleeping.

[0339] In another example, the ambient pressure may be the pressure immediately surrounding or external to the body.

[0340] In certain embodiments, ambient (e.g., acoustic) noise can be considered the background noise level in the room the patient is in, other than noise emanating from, for example, the RPT device or from the mask or patient interface. Ambient noise can originate from sources outside the room.

[0341] Automatic Positive Airway Pressure (APAP) Therapy: A CPAP therapy that is capable of automatically adjusting therapeutic pressure between minimum and maximum limits, for example, between breaths, depending on the presence or absence of signs of an SDB episode.

[0342] Continuous Positive Airway Pressure (CPAP) Therapy: Respiratory pressure therapy in which the therapeutic pressure is approximately constant throughout the patient's respiratory cycle. In some forms, the pressure at the entrance to the airways increases slightly during exhalation and decreases slightly during inhalation. In some forms, the pressure varies during different respiratory cycles of the patient (e.g., increased in response to the detection of an indication of partial upper airway obstruction and decreased in the absence of notification of partial upper airway obstruction).

[0343] Flow Rate: The instantaneous amount (or mass) of air delivered per unit time. Flow rate can refer to an instantaneous quantity. In some cases, reference to flow rate refers to a scalar quantity (i.e., a quantity that has only magnitude). In other cases, reference to flow rate refers to a vector quantity (i.e., a quantity that has both magnitude and direction). Flow rate may be given the symbol Q. "Flow rate" may also be simply called "flow."

[0344] In the example of patient breathing, the flow rate may be nominally positive for the inspiratory portion of the patient's respiratory cycle, and therefore negative for the expiratory portion of the patient's respiratory cycle. Total flow rate Qt is the flow rate of air exiting the RPT device. Vent flow rate Qv is the flow rate of air exiting the vent to allow for the outflow of exhaled gases. Leakage flow rate Ql is the flow rate of leakage from the patient interface system or elsewhere. Respiratory flow rate Qr is the flow rate of air received into the patient's respiratory system.

[0345] Leakage: The term "leakage" refers to unintended airflow. In one example, a leak can occur due to an imperfect seal between the mask and the patient's face. In another example, a leak can occur at the swivel elbow to the perimeter.

[0346] Noise Conduction (Acoustic): In this document, conducted noise refers to noise carried to the patient by the pneumatic path (e.g., the air circuit and patient interface and the air therein). In one form, conducted noise can be quantified by measuring the sound pressure level at the end of the air circuit.

[0347] Noise Emission (Acoustic): In this document, radiated noise refers to noise carried by the ambient air to the patient. In one form, radiated noise can be quantified by measuring the sound power / pressure level of the target in accordance with ISO 3744.

[0348] Ventilation noise (acoustic): In this document, ventilation noise refers to the noise generated by airflow through any ventilation (eg, ventilation holes in the patient interface).

[0349] Patient: A person with or without a respiratory disease.

[0350] Pressure: Force per unit area. Pressure can be expressed and measured in a variety of units (e.g., cmH2O, gf / cm 2 , and hectopascals). 1cmH2O is 1g-f / cm 2 which is approximately 0.98 hectopascals. In this specification, pressures are given in units of cmH2O unless otherwise specified.

[0351] The pressure in the patient interface is designated by the symbol Pm, and the therapeutic pressure, which represents the target value that the mask pressure Pm should achieve at this time, is designated by the symbol Pt.

[0352] Respiratory Pressure Therapy (RPT): The application to the airway entrance of an air supply at therapeutic pressure, typically positive pressure relative to atmosphere.

[0353] Ventilator: A mechanical device that provides pressure support to a patient while they perform some or all of the work of breathing.

[0354] 8.6.1.1 Materials Silicone or silicone elastomer: Synthetic rubber. References to silicone herein refer to liquid silicone rubber (LSR) or compression molded silicone rubber (CMSR). One commercially available form of LSR is SILASTIC (in a family of products sold under this registered trademark) manufactured by Dow Corning. Another LSR manufacturer is Wacker. Unless otherwise specified, exemplary forms of LSR have a Shore A (or Type A) indentation hardness of about 35 to about 45, as measured by ASTM D2240.

[0355] Polycarbonate: A transparent thermoplastic polymer, typically of bisphenol A carbonate.

[0356] 8.6.1.2 Mechanical properties Elasticity: The ability of a material to absorb energy during elastic deformation and to release the energy when unloaded. "Elastic": Releases substantially all of its energy upon unloading. Includes, for example, certain silicone and thermoplastic elastomers.

[0357] Hardness: The ability of a material to resist deformation (e.g., as described by Young's modulus or the indentation hardness scale measured on a standardized sample size). "Soft" materials may include silicone or thermoplastic elastomers (TPEs) and may easily deform under finger pressure, for example. "Hard" materials may include polycarbonate, polypropylene, steel or aluminum, and do not easily deform under finger pressure, for example.

[0358] Stiffness (or rigidity) of a structure or component: The ability of a structure or component to resist deformation when subjected to a load. The load can be a force or a moment (e.g., compression, extension, bending, or torsion). A structure or component may offer different resistance in different directions. "Floppy" structure or component: a structure or component that changes shape (e.g., flexes) within a relatively short period of time (e.g., 1 second) when forced to support its own weight. "Rigid" structure or component: a structure or component that does not substantially change shape when subjected to loads typically encountered in use. An example of such an application is a patient interface that is approximately 20-30 cmH 2 It can be set up and maintained in a sealed manner against the entrance to the patient's airway under pressure loading of O2.

[0359] As one example, an I-beam may have a different bending stiffness (resistance to bending load) in a first direction compared to a second, orthogonal direction. In another example, a structure or component may be floppy in a first direction and rigid in a second direction.

[0360] 8.6.2 Breathing Cycle Apnea: According to some definitions, apnea is said to occur when flow below a predetermined threshold continues for a duration of, for example, 10 seconds. Obstructive apnea is said to occur when some airway obstruction does not allow airflow despite patient effort. Central apnea is said to refer to a condition in which apnea is detected due to reduced or absent respiratory effort despite a patent airway. Mixed apnea is said to refer to a condition in which reduced or absent respiratory effort occurs simultaneously with airway obstruction.

[0361] Respiratory rate: The patient's spontaneous breathing rate, usually measured in breaths per minute.

[0362] Duty cycle: The ratio of inspiration time Ti to total breathing time Ttot.

[0363] Exercise (Respiration): Respiratory effort is said to refer to the movement made by the spontaneous breathing of a person trying to breathe.

[0364] Expiratory portion of the respiratory cycle: the period from the start of expiratory flow to the start of inspiratory flow.

[0365] Flow limitation: Flow limitation is understood to be a condition in a patient's breathing where an increase in patient effort does not result in a corresponding increase in flow. If flow limitation occurs during the inspiratory portion of the respiratory cycle, the flow limitation can be referred to as inspiratory flow limitation. If flow limitation occurs during the expiratory portion of the respiratory cycle, the flow limitation can be referred to as expiratory flow limitation.

[0366] Flow-limited inspiration waveform types: (i) Flattening: An upswing followed by a relatively flat area, followed by a downswing. (ii) M-shaped: has two local peaks, one on the rise and one on the fall, with a relatively flat region between these two peaks. (iii) Chair-like: A single local peak occurs at the rising edge, followed by a relatively flat region. (iv) Inverted chair: A relatively flat region is followed by a single local peak, which occurs at the trailing edge.

[0367] Hypopnea: By some definitions, hypopnea refers to a reduction in flow, rather than an interruption of flow. In one form, hypopnea is said to occur when flow is reduced below a threshold rate for a sustained period of time. When hypopnea is detected due to a decrease in respiratory effort, central hypopnea is said to occur. In one form, hypopnea may be considered when any of the following occur in adults: (i) A 30% decrease in patient respiration for at least 10 seconds plus an associated 4% desaturation, or (ii) A reduction in patient respiration (less than 50%) lasting at least 10 seconds and associated desaturation of at least 3% or arousal occurs.

[0368] Hyperventilation: An increase in flow to a level higher than normal.

[0369] Inspiratory portion of the respiratory cycle: The period from the start of the inspiratory flow to the start of the expiratory flow is taken as the inspiratory portion of the respiratory cycle.

[0370] Patency (Airway): The degree to which the airway is open or the extent to which it is open. Airway patency is an opening. Airway patency can be quantified, for example, with a value of 1 indicating open and a value of 0 indicating closed (obstructed).

[0371] Positive end-expiratory pressure (PEEP): The pressure above atmosphere in the lungs that exists at the end of expiration.

[0372] Peak flow (Qpeak): The maximum value of flow during the inspiratory portion of the respiratory flow waveform.

[0373] Respiratory airflow, airflow, patient airflow, respiratory airflow (Qr): These terms may be understood to refer to the RPT device's estimate of respiratory airflow, and are used in contrast to "true respiratory flow" or "true respiratory airflow," which is the patient's actual respiratory flow, usually expressed in liters / minute.

[0374] Tidal Volume (Vt): The volume of air inhaled or exhaled during normal breathing without extra effort.

[0375] (Inspiration) Time (Ti): The duration of the inspiratory portion of the respiratory flow waveform.

[0376] (Expiratory) Time (Te): The duration of the expiratory portion of the respiratory flow waveform.

[0377] (Total) Time (Ttot): The total duration between the start of one inspiratory portion of the respiratory flow waveform and the start of the next inspiratory portion of the respiratory flow waveform.

[0378] Typical Recent Ventilation: The ventilation value around which recent values of ventilationVent over a given time scale tend to cluster (i.e., the degree to which recent values of ventilation tend to be centered).

[0379] Upper Airway Obstruction (UAO): Includes both partial and total upper airway obstruction. May be associated with a state of flow limitation in which flow may increase or decrease slightly with increasing pressure differential across the upper airway (Starling resistor behavior).

[0380] Vent: A measure of the rate of gas exchange performed by a patient's respiratory system. Measurements of ventilation may include either or both inspiratory and expiratory flow per unit time. When expressed as volume per minute, this quantity is often referred to as "minute ventilation." Minute ventilation is sometimes given simply as volume and is understood as volume per minute.

[0381] 8.6.3 Ventilation Adaptive servo-ventilator (ASV): A servo-ventilator that does not have a fixed target ventilation but is variable. The variable target ventilation can be learned from some characteristic of the patient (e.g., the patient's breathing characteristics).

[0382] Backup Rate: A ventilator parameter that establishes the minimum respiratory rate (typically in breaths per minute) that will be delivered to the patient by the ventilator (when not triggered by spontaneous breathing efforts).

[0383] Cycle: The end of the inspiratory phase of a ventilator. When a ventilator delivers breaths to a spontaneously breathing patient, at the end of the inspiratory portion of the breathing cycle, the ventilator is said to be cycled to stop breath delivery.

[0384] Expiratory Positive Airway Pressure (EPAP): The base pressure to which varying pressures are added during a breath to produce the desired mask pressure that the ventilator attempts to achieve at a given moment.

[0385] End Expiratory Pressure (EEP): The desired mask pressure that the ventilator attempts to achieve at the end of the expiratory portion of the breath. If the pressure waveform template Π(Φ) has a value of zero at the end of expiration (i.e., Π(Φ)=0 when Φ=1), then EEP is equal to EPAP.

[0386] Inspiratory Positive Airway Pressure (IPAP): The maximum desired mask pressure that the ventilator attempts to achieve during the inspiratory portion of the breath.

[0387] Pressure support: A number indicating the increase in pressure during ventilator inspiration compared to the corresponding ventilator expiration, and refers primarily to the pressure difference between the peak inspiratory pressure and the base pressure (e.g., PS = IPAP - EPAP). In some contexts, pressure support refers to the difference the ventilator attempts to achieve (rather than the difference it actually achieves).

[0388] Servo-ventilator: A ventilator that has both patient ventilation and target ventilation, and adjusts the level of pressure support to bring the patient ventilation closer to the target ventilation.

[0389] Spontaneous / Timed (S / T): A mode of a ventilator or other device that attempts to detect the onset of a breath in a spontaneously breathing patient. However, if the device fails to detect a breath within a predetermined period of time, the device automatically begins breath delivery.

[0390] Swing: A term equivalent to pressure assistance.

[0391] Triggered: When a ventilator delivers a breath of air to a spontaneously breathing patient, the ventilator is said to be triggered to deliver a breath when the patient himself initiates the breathing portion of the breathing cycle.

[0392] Typical Recent Ventilation: Typical recent ventilation Vtyp is a range of values around which recent ventilation measurements tend to cluster over a given time scale. For example, a measure of the central tendency of ventilation measurements over recent history may be an appropriate value for typical recent ventilation.

[0393] 8.6.4 Anatomy 8.6.4.1 Facial Anatomy Ala: The outer wall or "wing" of each nostril (plural: alar)

[0394] Alare: The outermost point on the ala of the nose.

[0395] Alar curvature (or alar crest) point: The most posterior point on the curved baseline of each alar, found in the crease formed by the union of the alar and cheek.

[0396] Pinna: the entire visible part of the ear.

[0397] (Nasal) skeleton: The nasal skeleton includes the nasal bones, the frontal process of the maxilla, and the nasal portion of the frontal bone.

[0398] (Nasal) cartilaginous rami: The cartilaginous rami of the nose include the septal cartilage, lateral cartilage, greater cartilage, and lesser cartilage.

[0399] Columella: The piece of skin that separates the nostrils and extends from the tip of the nose to the upper lip.

[0400] Columella angle: the angle between a line drawn through the midpoint of the nostril and a line drawn perpendicular to the Frankfurt horizontal and intersecting the subnasal point.

[0401] Frankfort horizontal plane: A line extending from the most inferior point of the orbital rim to the left auricular point, which is the deepest point of the auricle from the superior side of the notch to the tragus.

[0402] Glabellar: Located in the soft tissue, the most prominent point in the midsagittal direction of the forehead.

[0403] Lateral nasal cartilage: a generally triangular plate of cartilage whose upper margin is attached to the nasal bone and the frontal process of the maxilla, and whose lower margin is connected to the greater alar cartilage.

[0404] Lip, lower side (lower lip: labrale inferius):

[0405] Lip, upper side (upper lip: labrale superius):

[0406] Greater alar cartilage: a cartilaginous plate located beneath the lateral nasal cartilage. It curves around the anterior part of the nostril. Its posterior end is connected to the frontal process of the maxilla by a tough fibrous membrane containing three or four alar cartilages.

[0407] Nostrils (nares): Generally ellipsoidal alar openings that form the entrance to the nasal cavity. The singular form of nostrils is naris (nose hole). These nostrils are separated by the nasal septum.

[0408] Nasolabial fold or nasolabial crease: a fold or groove of skin that extends from each side of the nose to the corners of the mouth, separating the cheek from the upper lip.

[0409] Nasolabial angle: the angle between the bridge of the nose and the upper lip, intersecting with the subnasal point.

[0410] Subbasal point of the ear: the lowest point of attachment of the pinna to the facial skin.

[0411] Suprabasal point of the ear: the highest point of attachment of the pinna to the facial skin.

[0412] Nasal tip: The most prominent point or tip of the nose, which can be seen in a lateral view of the rest of the head.

[0413] Philtrum: midline groove extending from the lower border of the nasal septum to the top of the lip in the upper lip area.

[0414] Pogonion: The most anterior midpoint of the jaw, located on the soft tissue.

[0415] Nasal ridge: The nasal ridge is the midline prominence of the nose, extending from the serion to the apex.

[0416] Sagittal plane: a vertical plane running from anterior (front) to posterior (back) that divides the body into right and left halves.

[0417] Cerion: Located on the soft tissue, it is the most concave point on the area of the frontonasal suture.

[0418] Septal cartilage (nose): The nasal septum cartilage is part of the septum, which divides the anterior part of the nasal cavity.

[0419] Nasal alar nasal basin: the point on the lower periphery of the alar base where it joins with the skin of the upper (top) lip.

[0420] Subnasal point: Located on the soft tissue, the point where the columella joins the upper lip in the midsagittal plane.

[0421] Supramentale: The most concave point in the midline of the lower lip between the lower lip midpoint and the soft tissue pogonion.

[0422] 8.6.4.2 Skull anatomy Frontal bone: The frontal bone contains the squama frontalis, a large vertical portion that corresponds to the area known as the forehead.

[0423] Mandible: The mandible forms the lower jaw. The mental protuberance is a bony protuberance in the jaw that forms the chin.

[0424] Maxilla: The maxilla forms the upper jaw and is located below the mandible and below the orbit. The frontal process of the maxilla projects upward by the sides of the nose and forms part of its lateral border.

[0425] Nasal bones: The nasal bones are two small, rectangular bones that vary in size and shape from person to person. They lie side by side in the middle and upper parts of the face, and their junction forms the "bridge" of the nose.

[0426] Nasion: the intersection of the frontal bone and the two nasal bones, a concave area directly between the eyes and the upper side of the bridge of the nose.

[0427] Occipital bone: The occipital bone is located at the back and underside of the skull. It contains the foramen magnum, an oval hole through which the intracranial cavity connects with the vertebral canal. The curved plate posterior to the foramen magnum is the squama occipitalis.

[0428] Orbit: bony cavity in the skull that contains the eyeball.

[0429] Parietal bones: The parietal bones are bones that, when joined together, form the top and sides of the skull.

[0430] Temporal bone: The temporal bone is located on the base and sides of the skull and supports parts of the face known as the temples.

[0431] Cheekbones: The two cheekbones in the face are located in the upper and outer parts of the face and form the cheek ridges.

[0432] 8.6.4.3 Respiratory System Anatomy Diaphragm: A sheet of muscle that runs over the lower rib cage. The diaphragm separates the thoracic cavity, which contains the heart, lungs, and ribs, from the abdominal cavity. When the diaphragm contracts, it increases the volume of the thoracic cavity and draws air into the lungs.

[0433] Larynx: The larynx or voice box that houses the vocal cords and connects the lower part of the pharynx (hypopharynx) to the trachea.

[0434] Lung: respiratory organ in humans. The conductive zone of the lung includes the trachea, bronchi, bronchi, and terminal bronchioles. The respiratory zone includes the respiratory bronchioles, alveolar ducts, and alveoli.

[0435] Nasal Cavity: The nasal cavity (or nasal fossa) is a large, air-filled space in the center of the face above and behind the nose. The nasal cavity is divided into two by a vertical fin called the nasal septum. The sides of the nasal cavity contain three horizontal extensions called turbinates or nasal conchae. The nasal cavity opens anteriorly into the nose and posteriorly into the nasopharynx via the choanae.

[0436] Pharynx: The part of the throat located immediately below (inferior to) the nasal cavity and above the esophagus and larynx. The pharynx is traditionally divided into three parts: the nasopharynx (upper pharynx) (nasal part of the pharynx), the oropharynx (mid pharynx) (oral part of the pharynx), and the hypopharynx (low pharynx).

[0437] 8.6.5 Patient Interface Anti-asphyxiation valve (AAV): A component or subassembly of a mask system that vents to atmosphere in a fail-safe manner to reduce the risk of excessive CO2 rebreathing by the patient.

[0438] Elbow: An elbow is an example of a structure that directs the axis of airflow moving therethrough to change direction through an angle. In one form, the angle may be approximately 90 degrees. In another form, the angle may be greater than or less than 90 degrees. The elbow may have a generally circular cross section. In another form, the elbow may have an oval or rectangular cross section. In certain forms, the elbow may be rotatable relative to the mating component, for example, approximately 360 degrees. In certain forms, the elbow may be detachable from the mating component, for example, via a snap connection. In certain forms, the elbow may be assembled to the mating component via a one-time snap during manufacturing, but cannot be removed by the patient.

[0439] Frame: Frame is taken to mean the mask structure that supports the tensile load between two or more points that connect the headgear. A mask frame can be a non-airtight load-bearing structure in the mask. However, some forms of mask frames may be airtight.

[0440] Headgear: Headgear is taken to mean a form of positioning and stabilizing structure designed for use on the head. For example, the headgear may include a collection of one or more posts, ties, and stiffeners configured to position and hold the patient interface in place on the patient's face for delivery of respiratory therapy. Some ties are formed from a soft, flexible, elastic material (e.g., a layered composite of foam and fabric).

[0441] Membrane: Membrane is taken to mean a typically thin-walled element, preferably substantially non-resistant to bending and resistant to stretching.

[0442] Plenum Chamber: Mask plenum chamber is taken to mean a part of a patient interface having walls that at least partially enclose a volume of space, the air in the volume being pressurized to exceed atmospheric pressure in use. The shell may form part of the wall of the mask plenum chamber.

[0443] Seal: When used as a noun ("seal"), it can refer to a structure, and when used as a verb ("to seal"), it can refer to an effect. Two elements can be constructed and / or arranged to "seal" or achieve a "sealing" effect between them without the need for a separate "sealing" element itself.

[0444] Shell: A shell is taken to mean a curved, relatively thin structure that has bending, tensile, and compressive stiffness. For example, the curved structural wall of a mask may be a shell. In some forms, the shell may be faceted. In some forms, the shell may be airtight. In some forms, the shell may not be airtight.

[0445] Stiffener: A stiffener is taken to mean a structural component designed to increase the bending resistance of another component in at least one direction.

[0446] Strut: A strut is taken to mean a structural component designed to increase the compressive resistance of another component in at least one direction.

[0447] Swivel (noun): A subassembly of components configured to rotate, preferably independently, about a common axis, preferably under low torque. In one form, the swivel may be configured to rotate through an angle of at least 360 degrees. In another form, the swivel may be configured to rotate through an angle less than 360 degrees. When used in the context of an air delivery conduit, the subassembly of components preferably includes a mating cylindrical conduit. In use, the swivel exhibits little or no air leakage.

[0448] Tie (noun): A structure designed to resist tension.

[0449] Vent: (noun): A structure that allows airflow to the ambient atmosphere inside a mask or conduit, allowing clinically effective flushing of exhaled gases. For example, for clinically effective flushing, flow rates of about 10 liters / minute to about 100 liters / minute may be used depending on mask design and treatment pressure.

[0450] 8.7 Other Notes A portion of the disclosure of this patent document contains material that is entitled to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of this patent document or this patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but reserves all copyright rights therefor for all other purposes.

[0451] Unless otherwise clearly indicated from the context and unless a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit, between the upper and lower limits of the range, and for any other stated or intervening value in the stated range, is encompassed by the technology. The upper and lower limits of these intervening ranges, independently included in the intervening range, are also encompassed by the technology if they specifically exceed the limits in the stated range. If the stated range includes one or both of these limits, then ranges exceeding either or both of these stated limits are also encompassed by the technology.

[0452] Furthermore, when a value or values are embodied herein as part of the present technology, unless otherwise specified, it is understood that such values may be approximated and may be used to any appropriate significant figures to the extent practical technical practice permits or requires.

[0453] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this technology belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of this technology, a limited number of exemplary methods and materials are described herein.

[0454] Although particular materials are described as being suitable for use in the construction of components, obvious alternative materials having similar properties may be substituted. Furthermore, unless stated to the contrary, any and all components described herein are understood to be manufacturable and therefore may be manufactured collectively or separately.

[0455] Please note that as used herein and in the appended claims, the singular forms "a," "an," and "the" include their plural equivalents unless the context clearly dictates otherwise.

[0456] All publications mentioned herein are incorporated by reference to disclose and describe the methods and / or materials that are the subject of these publications. The publications mentioned herein are provided solely for their disclosure prior to the filing date of this application. Nothing herein should be construed as an admission that the present technology does not antedate such publications by virtue of prior patents. Furthermore, the dates of publications mentioned may differ from the actual publication dates, which may require independent confirmation.

[0457] The terms "comprises" and "comprising" should be construed as referring to elements, components, or steps in a non-exclusive sense, indicating that a described element, component, or step may be present in, utilized with, or combined with other elements, components, or steps not specifically described.

[0458] The headings used in the detailed description are for the convenience of the reader and should not be used to limit the content found in the disclosure or claims as a whole. These headings should not be used in interpreting the scope of the claims or the claim limitations.

[0459] Although the technology herein has been described with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the technology. In some cases, terms and symbols may indicate specific details unnecessary for the practice of the technology. For example, although the terms "first" and "second" (etc.) are used, unless otherwise specified, these terms are not intended to indicate any order but are used to distinguish between separate elements. Furthermore, although the process steps in the method may be described or illustrated in an ordered manner, such an order is not required. Those skilled in the art will recognize that such an order can be changed and / or aspects can be performed simultaneously or even synchronously.

[0460] It is therefore to be understood that numerous modifications may be made in the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present technology.

[0461] Furthermore, the present invention preferably includes the following examples. [Section 1] 1. A positioning and stabilising structure for maintaining a seal-forming structure in a therapeutically effective position on a patient's head, said seal-forming structure constructed and arranged to form a seal with an area of the patient's face surrounding an entrance to the patient's airway for sealed delivery of airflow at a therapeutic pressure of at least 4 cmH2O relative to ambient air pressure throughout the patient's respiratory cycle, said positioning and stabilising structure comprising: at least one gas delivery conduit for delivering the air flow through the seal-forming structure to an entrance of the patient's airway, the at least one gas delivery conduit constructed and arranged to contact, in use, at least an area of the patient's head above an ear base of the patient's head; an adjustment mechanism for adjusting the at least one gas delivery tube to allow the positioning and stabilizing structure to fit different sized heads; a biasing mechanism that, in use, applies a biasing force along at least a portion of the length of the at least one gas delivery tube to urge the seal-forming structure toward the entrance to the patient's airway; a positioning and stabilizing structure, including: [Section 2] Item 1, wherein the at least one gas delivery tube includes the adjustment mechanism. [Section 3] Item 3. The positioning and stabilizing structure of item 1 or 2, wherein the at least one gas delivery tube includes the biasing mechanism. [Section 4] 4. The positioning and stabilizing structure of any one of claims 1 to 3, further comprising a connection port that, in use, fluidly connects to an air circuit connected to a supply of pressurized air, the connection port being positioned near the top, side or back of the patient's head in use. [Section 5] Item 5. The positioning and stabilizing structure according to item 4, wherein the biasing mechanism includes an elastic member provided between the seal-forming structure and the connection port. [Section 6] Item 6. The positioning and stabilizing structure of item 5, wherein the elastic member includes an elastic sleeve, the gas delivery tube includes the elastic sleeve and an inner gas delivery conduit, and the elastic sleeve covers the inner gas delivery conduit. [Section 7] Item 6. The positioning and stabilizing structure of item 5, wherein the elastic member comprises a portion of the gas delivery tube formed from an elastic material. [Section 8] Item 6. The positioning and stabilizing structure of item 5, wherein the elastic member includes a portion of the gas delivery tube having a bellows structure. [Section 9] Item 9. The positioning and stabilizing structure of item 8, wherein the adjustment mechanism includes the bellows structure. [Section 10] Item 10. The positioning and stabilizing structure of item 8 or 9, wherein a portion of the gas delivery tube having the bellows structure is positioned in contact with an area of the patient's head above the ear base point of the patient's head during use. [Section 11] Item 11. The inflatable positioning and stabilizing structure of any one of items 1 to 10, wherein the adjustment mechanism allows the length of the at least one gas delivery tube to be adjusted over a continuous range of lengths. [Section 12] Item 12. The positioning and stabilizing structure of any one of items 1 to 11, wherein the gas delivery tube includes a first tube section and a second tube section, and the first tube section is telescopically movable relative to the second tube section to adjust the length of the tube. [Section 13] Item 13. The positioning and stabilizing structure of item 12, wherein the patient interface includes one or more tabs that facilitate relative telescopic movement between the first tube portion and the second tube portion. [Section 14] Item 14. The positioning and stabilizing structure of item 12 or 13, wherein the patient interface includes a tube section fixation mechanism that fixes the first and second tube sections in a plurality of discrete positions relative to each other. [Section 15] Item 15. The positioning and stabilizing structure of any one of items 1 to 14, wherein the gas delivery tube includes a folding portion such that the length of the gas delivery tube when the folding portion is in a folded configuration is different from the length of the gas delivery tube when the folding portion is in an unfolded configuration. [Section 16] Item 16. The positioning and stabilizing structure of item 15, wherein the gas delivery tube includes a plurality of folds in a portion of the gas delivery tube having a bellows structure. [Section 17] Item 17. The positioning and stabilizing structure of any one of items 1 to 16, wherein the adjustment mechanism includes an extendable portion of the gas delivery tube. [Section 18] Item 18. The positioning and stabilizing structure of any one of items 1 to 17, wherein the adjustment mechanism includes a first tube portion, the first tube portion being removable and replaceable with a second tube portion having a different length than the first tube portion. [Section 19] Item 19. The positioning and stabilizing structure of any one of items 1 to 18, wherein the adjustment mechanism includes one or more tube insert members configured to be selectively fluidly connected to the gas delivery tube to vary the length of the gas delivery tube. [Section 20] 20. The positioning and stabilizing structure of any one of claims 1 to 19, wherein the gas delivery tube includes multiple indicators that indicate where the gas delivery tube should be cut to fit different sized patient heads. [Section 21] 20. The positioning and stabilizing structure of any one of claims 1 to 19, wherein the adjustment mechanism is configured to allow the at least one gas delivery tube to be bendably adjusted to fit the positioning and stabilizing structure to heads of different sizes. [Section 22] Item 22. The positioning and stabilizing structure of any one of items 1 to 21, wherein the positioning and stabilizing structure is configured to be positioned such that, in use, the adjustment mechanism does not come into contact with the patient's face. [Section 23] 23. The positioning and stabilising structure of claim 22, wherein the positioning and stabilising structure is configured such that, in use, the adjustment mechanism is positioned so as not to come into contact with the cheek region of the patient. [Section 24] Item 24. The positioning and stabilizing structure of item 23, wherein the adjustment mechanism is positioned above the supra-ear point of the patient's head in use. [Section 25] Item 25. The positioning and stabilizing structure of any one of items 1 to 24, wherein the positioning and stabilizing structure extends across the cheek region of the patient in use. [Section 26] 26. The positioning and stabilizing structure of any one of claims 1 to 25, wherein the positioning and stabilizing structure does not include any mechanism that allows for length adjustment of the at least one gas delivery tube below the supra-ear point of the patient's head. [Section 27] Item 27. The positioning and stabilizing structure of item 26, wherein the positioning and stabilizing structure does not include any mechanism that allows for adjustment of the length of the at least one gas delivery tube that extends across the patient's cheek area in use. [Section 28] 28. The positioning and stabilizing structure of any one of claims 25 to 27, wherein the positioning and stabilizing structure includes two gas delivery tubes fluidly connected between the connection port and the seal-forming structure, each gas delivery tube extending across one of the patient's cheek regions in use, and the two gas delivery tubes being located on different sides of the patient's head. [Section 29] The positioning and stabilizing structure of any one of clauses 4 to 28 when dependent on clause 4, wherein the connection port is located on the top of the patient's head in use. [Section 30] 30. The positioning and stabilising structure of clause 29, wherein the positioning and stabilising structure, in use, extends between the patient's eye and the patient's ear. [Section 31] 30. The positioning and stabilizing structure of claim 29, wherein the positioning and stabilizing structure includes a rear strap connected between the two gas delivery tubes and configured to pass behind the patient's head in use. [Section 32] Item 32. The positioning and stabilizing structure of item 31, wherein the length of the rear strap between the two gas delivery tubes is adjustable. [Section 33] Item 33. The positioning and stabilizing structure of item 31 or 32, wherein the angle of the rear strap relative to each gas delivery tube is adjustable. [Section 34] 34. The positioning and stabilizing structure of any one of claims 31 to 33, wherein the positioning and stabilizing structure includes an adjustment mechanism that is positioned above the point where the rear strap is connected to one of the gas delivery tubes in use, and the positioning and stabilizing structure does not include any mechanism that allows for length adjustment of the at least one gas delivery tube that is positioned below the point where the rear strap is connected to one of the gas delivery tubes in use. [Section 35] A patient interface comprising: a plenum chamber pressurizable to a therapeutic pressure of at least 4 cmH2O above ambient air pressure, said plenum chamber including a plenum chamber inlet port sized and configured to receive airflow at the therapeutic pressure for breathing by a patient; a seal-forming structure constructed and arranged to form a seal against an area of the patient's face surrounding an entrance to the patient's airways, whereby a flow of air at said therapeutic pressure is delivered to at least an entrance to the patient's nares, the seal-forming structure constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout the patient's respiratory cycle, in use; a connection port for fluidly connecting to an air circuit connected to said air flow in use, said connection port being positioned adjacent to the top, side or back of a patient's head in use; A positioning and stabilizing structure for maintaining the seal-forming structure in a therapeutically effective position on the patient's head, the positioning and stabilizing structure comprising: at least one gas delivery conduit for delivering a flow of air through the seal-forming structure to an entrance of the patient's airway, the at least one gas delivery conduit constructed and arranged to contact, in use, at least one region of the patient's head above an ear-base point of the patient's head; an adjustment mechanism for adjusting the at least one gas delivery tube to allow the positioning and stabilizing structure to fit different sized heads; and a positioning and stabilising structure including a biasing mechanism that, in use, applies a biasing force along at least a portion of a length of the at least one gas delivery tube to urge the seal-forming structure towards the entrance to the patient's airway; and a patient interface including: [Section 36] 1. A system for treating a respiratory disorder, said system comprising: Item 36. A patient interface according to item 35; air circuits; and An air source with positive pressure relative to the ambient air pressure Including, the system. [Section 37] 1. A positioning and stabilising structure for maintaining a seal-forming structure in a therapeutically effective position on a patient's head, said seal-forming structure constructed and arranged to form a seal with an area of the patient's face surrounding an entrance to the patient's airway for sealed delivery of airflow at a therapeutic pressure of at least 4 cmH2O relative to ambient air pressure throughout the patient's respiratory cycle, said positioning and stabilising structure comprising: at least one tie configured to contact the patient's head in use, the at least one tie comprising: at least one tie including at least one gas delivery tube for delivering the air flow through the seal-forming structure to an entrance of the patient's airway, the at least one gas delivery tube being constructed and arranged, in use, to cover at least an area of the patient's head above an ear base of the patient's head; an adjustment mechanism for adjusting the at least one tie to allow the positioning and stabilizing structure to fit different sized heads; The positioning and stabilising structure is configured such that, in use, the adjustment mechanism is positioned so as not to contact the patient's face. [Section 38] Item 38. The positioning and stabilizing structure of item 37, wherein the at least one gas delivery tube includes the adjustment mechanism. [Section 39] Item 39. The positioning and stabilizing structure of item 37 or 38, wherein the at least one gas delivery tube includes the biasing mechanism. [Section 40] 40. The positioning and stabilizing structure of any one of clauses 37 to 39, further comprising a connection port for fluid connection to an air circuit connected in use to a supply of pressurized air, the connection port being positioned in use near the top, side or back of the patient's head. [Section 41] 41. The positioning and stabilizing structure of any one of clauses 37 to 40, wherein the positioning and stabilizing structure is configured such that, in use, the adjustment mechanism is positioned so as not to come into contact with the cheek region of the patient. [Section 42] 42. The positioning and stabilizing structure of any one of claims 37 to 41, wherein in use the adjustment mechanism is positioned above the supra-ear point of the patient's head. [Section 43] 43. The positioning and stabilizing structure of any one of claims 37 to 42, wherein the positioning and stabilizing structure includes a biasing mechanism that, in use, applies a biasing force along at least a portion of the length of the at least one gas delivery tube to urge the seal-forming structure into the region surrounding the entrance to the patient's airway. [Section 44] Item 44. The positioning and stabilizing structure according to item 43, wherein the biasing mechanism includes an elastic member provided between the seal-forming structure and the connection port. [Section 45] Item 45. The positioning and stabilizing structure of item 44, wherein the elastic member includes an elastic sleeve, the gas delivery tube includes the elastic sleeve and an inner gas delivery conduit, and the elastic sleeve covers the inner gas delivery conduit. [Section 46] 45. The positioning and stabilizing structure of claim 44, wherein the elastic member comprises a portion of the gas delivery tube formed from an elastic material. [Section 47] Item 45. The positioning and stabilizing structure of item 44, wherein the elastic member comprises a portion of the gas delivery tube having a bellows structure. [Section 48] Item 48. The positioning and stabilizing structure of item 47, wherein the adjustment mechanism includes the bellows structure. [Section 49] Item 49. The positioning and stabilizing structure of claim 47 or 48, wherein a portion of the gas delivery tube having the bellows structure is positioned in contact with an area of the patient's head above the ear base of the patient's head during use. [Section 50] 50. The positioning and stabilizing structure of any one of claims 37 to 49, wherein the at least one gas delivery tube has a wavy shape along its length. [Section 51] 50. The positioning and stabilising structure of any one of clauses 37 to 49, wherein the adjustment mechanism allows for adjustment of the length of the at least one tie. [Section 52] Item 52. The positioning and stabilizing structure of item 51, wherein the adjustment mechanism allows the length of the at least one tie to be adjusted through a continuous range of lengths. [Section 53] 53. The positioning and stabilizing structure of any one of clauses 37 to 52, wherein the adjustment mechanism allows for adjustment of the length of the at least one gas delivery tube. [Section 54] 54. The positioning and stabilizing structure of claim 52 or 53, wherein the gas delivery tube includes a first tube portion and a second tube portion, the first tube portion being telescopically movable relative to the second tube portion to adjust the length of the gas delivery tube. [Section 55] 55. The positioning and stabilizing structure of clause 54, wherein the patient interface includes one or more tabs for facilitating relative telescopic movement between the first tube portion and the second tube portion. [Section 56] 56. The positioning and stabilizing structure of claim 54 or 55, wherein the patient interface includes a tube section fixing mechanism for fixing the first and second tube sections to each other at a plurality of distinct positions. [Section 57] Item 57. The positioning and stabilizing structure of any one of items 37 to 56, wherein the gas delivery tube includes a folding portion such that the length of the gas delivery tube when the folding portion is in a folded configuration is different from the length of the gas delivery tube when the folding portion is in an unfolded configuration. [Section 58] Item 58. The positioning and stabilizing structure of item 57, wherein the gas delivery tube includes a plurality of folds in a portion of the gas delivery tube having a bellows structure. [Section 59] Item 59. The positioning and stabilizing structure of any one of items 37 to 58, wherein the adjustment mechanism includes an extendable portion of the gas delivery tube. [Section 60] Item 59. The positioning and stabilizing structure of any one of items 37 to 59, wherein the adjustment mechanism includes a first tube portion that is removable and can be replaced with a second tube portion having a different length than the first tube portion. [Section 61] Item 61. The positioning and stabilizing structure of any one of items 37 to 60, wherein the adjustment mechanism includes one or more tube insert members configured to be selectively fluidly connected to the gas delivery tube to vary the length of the gas delivery tube. [Section 62] Item 62. The positioning and stabilizing structure of any one of items 37 to 61, wherein the gas delivery tube includes multiple indicators that indicate where the gas delivery tube should be cut to fit different sized patient heads. [Section 63] Item 63. The positioning and stabilizing structure of any one of items 37 to 62, wherein the adjustment mechanism is configured to allow the at least one gas delivery tube to be bendably adjusted to fit the positioning and stabilizing structure to heads of different sizes. [Section 64] 64. The positioning and stabilizing structure of any one of clauses 37 to 63, wherein the at least one tie defines a loop configured to encircle a portion of the patient's head in use, the at least one gas delivery tube defines at least a portion of the loop, and the positioning and stabilizing structure includes a loop adjustment mechanism operable to adjust the position at which two regions of the at least one tie are held together to adjust the size of the loop. [Section 65] 63. The positioning and stabilizing structure of any one of claims 37 to 62, wherein the at least one tie defines a loop configured to encircle a portion of the patient's head in use, the at least one gas delivery tube defines at least a portion of the loop, and the positioning and stabilizing structure includes a loop insert configured to be secured directly or indirectly to the at least one gas delivery tube in use, the loop insert defining at least a portion of the loop. [Section 66] Item 66. The positioning and stabilizing structure of Item 65, wherein the loop insert is inflatable. [Section 67] 67. The positioning and stabilizing structure of claim 65 or 66, wherein the loop insert member is configured to be replaced with a replacement loop insert member of a different size to adjust the size of the loop. [Section 68] Item 68. The positioning and stabilizing structure of any one of items 37 to 67, wherein the adjustment mechanism is positioned above the supra-ear point of the patient's head in use. [Section 69] Item 69. The positioning and stabilizing structure of any one of items 37 to 68, wherein the positioning and stabilizing structure extends across the cheek region of the patient in use. [Section 70] Item 69. The positioning and stabilizing structure of any one of items 37 to 69, wherein the positioning and stabilizing structure does not include any mechanism for allowing adjustment of the length of the at least one tie below the supra-ear point of the patient's head. [Section 71] Item 71. The positioning and stabilizing structure of item 70, wherein the positioning and stabilizing structure does not include any mechanism that allows for adjustment of the length of the at least one tie that extends across the patient's cheek area in use. [Section 72] 72. The positioning and stabilizing structure of any one of claims 69 to 71, wherein the positioning and stabilizing structure includes two gas delivery tubes fluidly connected between the connection port and the seal-forming structure, each gas delivery tube extending across one of the patient's cheek regions in use, and the two gas delivery tubes being on different sides of the patient's head. [Section 73] The positioning and stabilising structure of any one of clauses 40 to 72 when dependent on clause 40, wherein the connection port is positioned on top of the patient's head in use. [Section 74] Item 74. The positioning and stabilizing structure of item 73, wherein the positioning and stabilizing structure, in use, extends between the patient's eye and the patient's ear. [Section 75] Item 73. The positioning and stabilizing structure of item 72, wherein the at least one tie includes a rear strap connected between the two gas delivery tubes and configured to pass around the rear of the patient's head in use. [Section 76] Item 76. The positioning and stabilizing structure of item 75, wherein the length of the rear strap between the two gas delivery tubes is adjustable. [Section 77] 77. The positioning and stabilizing structure of claim 75 or 76, wherein the angle of the rear strap relative to each gas delivery tube is adjustable. [Section 78] 78. The positioning and stabilizing structure of any one of claims 75 to 77, wherein the positioning and stabilizing structure includes an adjustment mechanism that is positioned above the point where the rear strap connects to one of the gas delivery tubes in use, and the positioning and stabilizing structure does not include any mechanism that allows adjustment of the at least one tie that is positioned below the point where the rear strap connects to one of the gas delivery tubes in use. [Section 79] A patient interface comprising: a plenum chamber pressurizable to a therapeutic pressure of at least 4 cmH2O above ambient air pressure, said plenum chamber including a plenum chamber inlet port sized and configured to receive airflow at the therapeutic pressure for breathing by a patient; a seal-forming structure constructed and arranged to form a seal against an area of the patient's face surrounding an entrance to the patient's airways, whereby a flow of air at said therapeutic pressure is delivered to at least an entrance to the patient's nares, the seal-forming structure constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout the patient's respiratory cycle, in use; a connection port for fluidly connecting to an air circuit connected to said air flow in use, said connection port being positioned adjacent to the top, side or back of a patient's head in use; A positioning and stabilizing structure for maintaining the seal-forming structure in a therapeutically effective position on the patient's head, the positioning and stabilizing structure comprising: at least one tie configured to contact the patient's head in use, the at least one tie comprising: at least one tie including at least one gas delivery tube for delivering the air flow through the seal-forming structure to an entrance of the patient's airway, the at least one gas delivery tube being constructed and arranged, in use, to cover at least an area of the patient's head above an ear base of the patient's head; an adjustment mechanism for adjusting the at least one tie to allow the positioning and stabilizing structure to fit different sized heads; Including, the positioning and stabilizing structure is configured to be positioned such that, in use, the adjustment mechanism does not contact the patient's face; and a patient interface including: [Section 80] 1. A system for treating a respiratory disorder, said system comprising: 80. A patient interface according to clause 79; air circuits; and An air source with positive pressure relative to the ambient air pressure Including, the system. [Section 81] A patient interface comprising: a plenum chamber pressurizable to a therapeutic pressure of at least 4 cmH2O above ambient air pressure, said plenum chamber including a plenum chamber inlet port sized and configured to receive airflow at the therapeutic pressure for breathing by a patient; a seal-forming structure constructed and arranged to form a seal against an area of the patient's face surrounding an entrance to the patient's airways, whereby a flow of air at said therapeutic pressure is delivered to at least an entrance to the patient's nares, the seal-forming structure constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout the patient's respiratory cycle, in use; a positioning and stabilizing structure for holding the seal-forming structure in a therapeutically effective position on the patient's head, a first tube portion constructed and arranged in use to cover an area of the patient's head above the ear base of the patient's head; and a positioning and stabilizing structure including a tie portion that, in use, rests on or covers the rear of the occipital bone of the patient's head; a positioning structure including: a venting structure that allows a continuous flow of gases exhaled by the patient from within the plenum chamber to the surroundings, the venting structure being sized and shaped to maintain the therapeutic pressure within the plenum chamber in use; Including, the first tubing is configured to conduct at least a portion of the airflow breathed by the patient; the first tube portion is configured to be taut in use; A patient interface, wherein the first tube portion includes a lengthwise adjustment mechanism. [Section 82] Item 82. A patient interface as described in paragraph 81, wherein the positioning and stabilizing structure includes a second tube portion configured to cover the maxillary region of the patient's head in use and to connect to the plenum chamber in use. [Section 83] 83. A patient interface as described in paragraph 81 or 82, wherein the patient interface further includes a connection port configured to receive an air supply and deliver the air supply to the first tube portion. [Section 84] Item 84. A patient interface as described in paragraph 83, wherein the connection port is constructed and arranged to be located on the top of the patient's head when in use. [Section 85] A patient interface as described in any one of clauses 81 to 84, wherein the positioning and stabilizing structure includes a third tube portion configured to connect to the connection port and to cover the area of the patient's head above the ear base point of the patient's head in use. [Section 86] 86. A patient interface as described in any one of clauses 81 to 85, wherein the positioning and stabilizing structure includes a fourth tube portion configured to cover the maxillary region of the patient's head in use and to connect to the plenum chamber in use. [Section 87] 87. A patient interface according to any one of clauses 81 to 86, wherein the seal-forming structure is configured to expose the patient's oral cavity in use. [Section 88] 88. A patient interface according to any one of clauses 81 to 87, wherein the seal-forming structure is configured such that no part of the seal-forming structure enters the oral cavity in use. [Section 89] 89. A patient interface according to any one of clauses 81 to 88, wherein the seal-forming structure is configured such that the seal-forming structure does not extend into the patient's airway. [Section 90] 90. A patient interface according to any one of clauses 81 to 89, wherein the seal-forming structure is configured such that, in use, the seal-forming structure does not extend below the chin prominence area. [Section 91] 91. A patient interface according to any one of clauses 81 to 90, wherein the patient interface is constructed and arranged so that the plenum chamber does not cover the eye when in use. [Section 92] 1. A positioning and stabilising structure for maintaining a seal-forming structure in a therapeutically effective position on a patient's head, said seal-forming structure constructed and arranged to form a seal with an area of the patient's face surrounding an entrance to the patient's airway for sealed delivery of airflow at a therapeutic pressure of at least 4 cmH2O relative to ambient air pressure throughout the patient's respiratory cycle, said positioning and stabilising structure comprising: a first conduit portion constructed and arranged, in use, to cover an area of the patient's head above the ear base of the patient's head; and a tie portion that, in use, rests on or covers the rear of the occipital bone of the patient's head; Including, the first conduit portion is configured to conduct at least a portion of the airflow breathed by the patient; the first conduit portion is configured to be taut in use; The first conduit portion includes a longitudinal adjustment mechanism and a positioning and stabilizing structure. [Section 93] A patient interface comprising: a plenum chamber pressurizable to a therapeutic pressure of at least 4 cmH2O above ambient air pressure, said plenum chamber including a plenum chamber inlet port sized and configured to receive airflow at the therapeutic pressure for breathing by a patient; a seal-forming structure constructed and arranged to form a seal against an area of the patient's face surrounding an entrance to the patient's airways, whereby a flow of air at said therapeutic pressure is delivered to at least an entrance to the patient's nares, the seal-forming structure constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout the patient's respiratory cycle, in use; 1. A positioning and stabilizing structure that provides a resilient force to hold a seal-forming structure in a therapeutically effective position on a patient's head for hermetically delivering said therapeutic pressure in said air flow, said positioning and stabilizing structure comprising: a tie constructed and arranged such that at least a portion of the tie, in use, covers an area of the patient's head above an ear-base point of the patient's head, the tie including an adjustable length gas delivery tube for delivering the airflow through the seal-forming structure to an entrance to the patient's airway, the gas delivery tube configured to contact a portion of the patient's head in use; and a biasing mechanism that applies a biasing force to the adjustable length gas delivery tube to urge the seal-forming structure toward the entrance of the patient's airway in use; a positioning and stabilizing structure including: a patient interface including: [Section 94] Item 94. A patient interface as described in paragraph 93, wherein the adjustable length gas delivery tube includes an extendable portion. [Section 95] 95. A patient interface as described in clause 94, wherein the extensible portion is configured such that the extensible portion avoids contact with the patient's face in use. [Section 96] 96. A patient interface as described in clause 95, wherein the extensible portion is configured such that the extensible portion is positioned above the supra-ear point of the patient's head in use. [Section 97] 97. The patient interface of any one of clauses 94 to 96, wherein the extensible portion comprises a bellows structure. [Section 98] Item 98. A patient interface as described in Item 97, wherein the bellows structure includes one or more elastic sections, the one or more elastic sections configured to expand and contract during use to allow adjustment of the length of the gas delivery tube. [Section 99] 99. A patient interface as described in paragraph 97 or 98, wherein the bellows structure includes one or more elastic portions, the one or more elastic portions configured to retract to apply the biasing force onto the adjustable length gas delivery tube. [Section 100] 99. A patient interface as described in any one of clauses 93 to 99, wherein the adjustable length gas delivery tube further comprises a bendable portion to allow adjustment of the position of the adjustable length gas delivery tube on the patient's head during use. [Section 101] 101. A patient interface as described in clause 100, wherein the bendable portion is configured such that the bendable portion is positioned above the ear base of the patient's head in use. [Section 102] Item 102. A patient interface as described in paragraph 101, wherein the bendable portion is configured to decouple positional adjustment of the adjustable length gas delivery tube from movement of the seal-forming structure away from the patient's face during use. [Section 103] 103. The patient interface of any one of clauses 100 to 102, wherein the bendable section comprises one or more elastic sections. [Section 104] 1. A positioning and stabilising structure for maintaining a seal-forming structure in a therapeutically effective position on a patient's head, said seal-forming structure constructed and arranged to form a seal with an area of the patient's face surrounding an entrance to the patient's airway for sealed delivery of airflow at a therapeutic pressure of at least 4 cmH2O relative to ambient air pressure throughout the patient's respiratory cycle, said positioning and stabilising structure comprising: a tie constructed and arranged such that at least a portion of the tie, in use, covers an area of the patient's head above an ear-base point of the patient's head, the tie including an adjustable length gas delivery tube for delivering the airflow through the seal-forming structure to an entrance to the patient's airway, the gas delivery tube configured to contact a portion of the patient's head in use; and a biasing mechanism that applies a biasing force to the adjustable length gas delivery tube to urge the seal-forming structure toward the entrance of the patient's airway in use; a positioning and stabilizing structure, including: [Explanation of symbols]

[0462] 1000 patients 1100 Bedmate 3000 Patient Interface 3100 Sealing or seal-forming structures 3150 Cushion Assembly 3170 Nose seal forming structure 3180 Mouth seal forming structure 3200 Plenum Chamber 3210 Plenum chamber edge 3300 Positioning and Stabilizing Structure / Headgear 3310 Headgear Strap 3320 Chin strap 3330 Padded member 3340 Elastic sleeve 3342 Side opening 3343 Upper opening 3345 tabs 3347 Curved Edge 3348 Patient Contact 3349 Non-patient contact side 3350 Headgear Pipe 3351 Upper tube member 3352 Tube end 3353A Upper curved part 3353B Lower curved part 3354 Not very extensible pipe section 3355 Extendable pipe section 3356 Fixing mechanism 3357 First fixing member 3358 Second fixing member 3360 Adjustment Mechanism 3362 Bellows tube 3363 Non-adjustable headgear tube 3364 Folding section 3366 Pipe wall folding / rotation folding part 3368 Adjacent pipe section 3370 First Pipe Section 3371 First Tab 3372 Second Pipe Section 3373 Second Tab 3374 Ribs 3375 Nested concentric tube section 3376 Ratchet mechanism 3377 Visual Indicator 3378 Button 3379 Hardened materials 3380 First screw part 3382 Second screw part 3383 Pinion 3384 Ring member 3385 Replaceable tube section 3386 Replacement tube 3387 Pipe inserts 3390 Strap 3391 Strap adjustment mechanism 3395 band 3397 Tongs 3398 Groove 3410 Loop insert member 3411 Replacement loop insert 3420 Expandable loop insert 3600 connection port 3744 ISO 4000 RPT devices 4010 Outer Housing 4012 Upper part 4014 parts 4015 Panel 4016 chassis 4018 Handle 4020 Pneumatic Block 4100 Pneumatic Components 4110 Air Filter 4112 Inlet Air Filter 4114 Outlet air filter 4122 Inlet muffler 4124 Exit muffler 4140 Pressure Generator 4142 Controllable Blower 4144 Air Circuit 4200 Electrical Components 4202 Printed Circuit Board Assembly (PCBA) 4210 Power supply 4220 input devices 4230 Central Controller 4240 Therapy Device Controller 4250 protection circuit 4260 memory 4270 Converter 4272 Pressure Sensor 4274 Flow Sensor 4280 data communications interface 4290 output device 4300 Algorithm 5000 humidifier 5002 Humidifier inlet 5004 Humidifier outlet 5006 Humidifier Base 5110 Humidifier Reservoir 5130 Humidifier Reservoir Dock 5240 heating element 6000 Force-Extension Plot 6100 Extension axis 6105 Zero extension 6110 First extension amount 6120 Second extension amount 6200 force axis 6210 Minimum sealing force 6220 Maximum Comfort 6300 Force-extension characteristics

Claims

1. A positioning and stabilizing structure configured to, in use, hold a cushion assembly of a patient interface in a therapeutically effective position on a patient's head so as to seal and deliver airflow at a therapeutic pressure of at least 4 cmH2O relative to ambient air pressure throughout the patient's respiratory cycle, comprising: two gas delivery tubes, each connected at a first end to a corresponding one of the inlet ports of the cushion assembly to deliver the air flow through the cushion assembly to an entrance to the patient's airway, each configured to be positioned on a corresponding side of the patient's head in use, each constructed and arranged to contact at least an area of ​​the patient's head above an ear base in use, each having a tab protruding in a generally posterior direction relative to the patient's head in use, the tab having a hole; a connection port configured, in use, to fluidly connect the two gas delivery tubes with an air circuit to deliver the air flow to the patient's airway, the connection port configured, in use, to be positioned above the patient's head; a sleeve constructed from a resilient material at least partially covering each of the two gas delivery tubes, the sleeve having a pair of side holes, the tabs of each of the gas delivery tubes extending through a corresponding one of the side holes; 1. A positioning and stabilizing structure comprising:

2. The positioning and stabilizing structure described in Claim 1, characterized in that the elastic material is an elastic fabric.

3. Further comprising an elbow including a first end rotatably connected to the positioning and stabilizing structure at the connection port and a second end having a swivel configured to be connected to the air circuit; 3. The positioning and stabilizing structure of claim 1, wherein the elbow is rotatable 360 ​​degrees about the connection port, the swivel is rotatable 360 ​​degrees about the second end of the elbow, and the elbow is configured to direct the air flow from the air circuit through the connection port to the gas delivery tube.

4. The positioning and stabilizing structure described in Claim 3, characterized in that the sleeve has a central hole, and the connection port is exposed through the central hole so that a first end of the elbow can be rotatably connected to the positioning and stabilizing structure at the connection port.

5. A positioning and stabilizing structure as described in any one of claims 1 to 4, characterized in that each of the two gas delivery tubes is configured to extend across a corresponding cheek area of ​​the patient when in use.

6. A positioning and stabilizing structure as described in any one of claims 1 to 5, characterized in that each of the two gas delivery tubes is configured to extend between the patient's corresponding eye and the patient's corresponding ear when in use.

7. A positioning and stabilizing structure as described in any one of claims 1 to 6, characterized in that each of the gas delivery tubes has a bellows portion, the bellows portion having greater flexibility than adjacent portions of the gas delivery tube.

8. A positioning and stabilizing structure as described in Claim 7, characterized in that each of the two gas delivery tubes varies in width and diameter along the length of each bellows portion.

9. A positioning and stabilizing structure as described in claim 7 or 8, characterized in that each of the two gas delivery tubes is tapered along the length of each bellows portion so that the width and diameter of each of the two gas delivery tubes at one end of the bellows portion is smaller than the width and diameter of each of the two gas delivery tubes at the other end of the bellows portion.

10. A positioning and stabilizing structure as described in any one of claims 7 to 9, characterized in that each bellows portion is located between a corresponding tab of the gas delivery tube and the connection port.

11. A positioning and stabilizing structure described in any one of claims 7 to 10, characterized in that the sleeve covers each bellows portion.

12. A positioning and stabilizing structure as described in any one of claims 7 to 11, characterized in that each bellows portion is positioned on a corresponding side of the gas delivery tube so as to be away from the patient's face during use.

13. A positioning and stabilizing structure as described in any one of claims 7 to 12, characterized in that each bellows portion is positioned on a corresponding one of the gas delivery tubes so as to be spaced away from the corresponding cheek of the patient during use.

14. A positioning and stabilizing structure as described in any one of claims 1 to 13, characterized in that each of the two gas delivery tubes is constructed from a relatively flexible material.

15. The positioning and stabilizing structure of claim 14, wherein the relatively flexible material is silicone.

16. A positioning and stabilizing structure as described in any one of claims 1 to 15, characterized in that the sleeve is constructed from a single sheet of elastic material.

17. A positioning and stabilizing structure as described in any one of claims 1 to 16, characterized in that the sleeve is made up of multiple sheets of elastic material connected together.

18. A positioning and stabilizing structure as described in any one of claims 1 to 17, characterized in that it further comprises an adjustable length rear strap, the end of which is configured to pass through the hole in the tab to removably connect the adjustable length rear strap to the gas delivery tube, and the adjustable length rear strap is configured to pass around a posterior portion of the patient's head in use.

19. The positioning and stabilizing structure described in Claim 18, characterized in that the length-adjustable rear strap is configured to rest on or cover the rear of the occipital bone of the patient's head when in use.

20. The positioning and stabilizing structure of claim 19, further comprising an adjustable length lower strap configured to pass behind the patient's head and under the patient's ears so as to be indirectly connected to the cushion assembly.

21. The positioning and stabilizing structure described in Claim 20, characterized in that the length-adjustable lower strap is not connected to the two gas delivery tubes.

22. A positioning and stabilizing structure as described in any one of claims 18 to 21, characterized in that the adjustable length rear strap comprises a loop material and a hook material portion, the loop material and the hook material portion configured to removably connect the adjustable length rear strap to the tab.

23. A patient interface for sealed delivery of airflow at a therapeutic pressure of at least 4 cmH2O relative to ambient air pressure throughout a patient's respiratory cycle, in use, said patient interface comprising:

1. A cushion assembly comprising: a plenum chamber pressurizable to the treatment pressure, the plenum chamber including a pair of plenum chamber inlet ports, each of the pair of plenum chamber inlet ports sized and configured to receive the flow of air at the treatment pressure for breathing by the patient; a nasal seal-forming structure configured to contact and form a seal against a patient's face and around the patient's nose in use, the nasal seal-forming structure having nasal openings configured to deliver the airflow at the therapeutic pressure to the patient's nares in use, the nasal seal-forming structure being joined to the plenum chamber; a cushion assembly comprising: A positioning and stabilising structure according to any one of claims 1 to 22; A patient interface comprising:

24. A patient interface as described in claim 23, characterized in that the plenum chamber is provided with a plurality of vents sized and shaped to maintain the therapeutic pressure within the plenum chamber and configured to allow exhaled gases to be exhausted from within the plenum chamber to the surrounding environment.

25. A patient interface as described in claim 23, characterized in that the cushion assembly includes a plurality of vents sized and shaped to maintain the therapeutic pressure within the plenum chamber and configured to allow expiratory gases to be exhausted from within the plenum chamber to the surrounding environment.

26. A patient interface as described in any one of claims 23 to 25, characterized in that the nasal seal forming structure is made of silicone.

27. ​​A patient interface as described in any one of claims 23 to 26, characterized in that the plenum chamber comprises a shell.

28. A patient interface as described in any one of claims 23 to 27, characterized in that the cushion assembly further comprises a mouth seal forming structure configured to seal around the patient's mouth in use, the mouth seal forming structure having a mouth hole configured to deliver the air flow at the treatment pressure to the patient's mouth in use, the mouth seal forming structure being joined to the plenum chamber.

29. A patient interface as described in Claim 28, characterized in that the mouth seal forming structure is composed of silicone.

30. A patient interface as described in claim 28 or 29, characterized in that the nasal seal forming structure and the mouth seal forming structure are integrally formed.

31. A patient interface as described in claim 28 or 29, characterized in that the nasal seal forming structure and the mouth seal forming structure are removably attached.

32. A patient interface as described in any one of claims 28 to 31, further comprising an anti-asphyxiation valve configured to allow the patient to breathe from their surroundings in the absence of the air flow at the therapeutic pressure.

Images